nih-gov/www.ncbi.nlm.nih.gov/books/NBK53758/index.html
2025-03-19 17:16:30 +00:00

481 lines
No EOL
76 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<!-- AppResources meta begin -->
<meta name="paf-app-resources" content="" />
<script type="text/javascript">var ncbi_startTime = new Date();</script>
<!-- AppResources meta end -->
<!-- TemplateResources meta begin -->
<meta name="paf_template" content="" />
<!-- TemplateResources meta end -->
<!-- Logger begin -->
<meta name="ncbi_db" content="books" /><meta name="ncbi_pdid" content="book-part" /><meta name="ncbi_acc" content="NBK53758" /><meta name="ncbi_domain" content="helptaxonomy" /><meta name="ncbi_report" content="record" /><meta name="ncbi_type" content="fulltext" /><meta name="ncbi_objectid" content="" /><meta name="ncbi_pcid" content="/NBK53758/" /><meta name="ncbi_pagename" content="NCBI Taxonomy - Taxonomy Help - NCBI Bookshelf" /><meta name="ncbi_bookparttype" content="chapter" /><meta name="ncbi_app" content="bookshelf" />
<!-- Logger end -->
<title>NCBI Taxonomy - Taxonomy Help - NCBI Bookshelf</title>
<!-- AppResources external_resources begin -->
<link rel="stylesheet" href="/core/jig/1.15.2/css/jig.min.css" /><script type="text/javascript" src="/core/jig/1.15.2/js/jig.min.js"></script>
<!-- AppResources external_resources end -->
<!-- Page meta begin -->
<meta name="robots" content="INDEX,FOLLOW,NOARCHIVE" /><meta name="citation_inbook_title" content="Taxonomy Help [Internet]" /><meta name="citation_title" content="NCBI Taxonomy" /><meta name="citation_publisher" content="National Center for Biotechnology Information (US)" /><meta name="citation_date" content="2020/02/11" /><meta name="citation_author" content="Conrad Schoch" /><meta name="citation_fulltext_html_url" content="https://www.ncbi.nlm.nih.gov/books/NBK53758/" /><link rel="schema.DC" href="http://purl.org/DC/elements/1.0/" /><meta name="DC.Title" content="NCBI Taxonomy" /><meta name="DC.Type" content="Text" /><meta name="DC.Publisher" content="National Center for Biotechnology Information (US)" /><meta name="DC.Contributor" content="Conrad Schoch" /><meta name="DC.Date" content="2020/02/11" /><meta name="DC.Identifier" content="https://www.ncbi.nlm.nih.gov/books/NBK53758/" /><meta name="description" content="The National Center for Biotechnology Information (NCBI) Taxonomy includes organism names and classifications for every sequence in the nucleotide and protein sequence databases of the International Nucleotide Sequence Database Collaboration (INSDC). It provides a framework for clustering elements within other domains of NCBI web pages, for internal linking between domains of the Entrez system and for linking out to taxon-specific external resources on the web and relevant publications. It is also the standard nomenclature and classification repository for the International Nucleotide Sequence Database Collaboration (INSDC) that comprises of GenBank, the European Molecular Biology Laboratory (EMBL) and DNA Data Bank of Japan (DDBJ). It consists of a curated set of names and classifications for all of the source organisms represented in the INSDC." /><meta name="og:title" content="NCBI Taxonomy" /><meta name="og:type" content="book" /><meta name="og:description" content="The National Center for Biotechnology Information (NCBI) Taxonomy includes organism names and classifications for every sequence in the nucleotide and protein sequence databases of the International Nucleotide Sequence Database Collaboration (INSDC). It provides a framework for clustering elements within other domains of NCBI web pages, for internal linking between domains of the Entrez system and for linking out to taxon-specific external resources on the web and relevant publications. It is also the standard nomenclature and classification repository for the International Nucleotide Sequence Database Collaboration (INSDC) that comprises of GenBank, the European Molecular Biology Laboratory (EMBL) and DNA Data Bank of Japan (DDBJ). It consists of a curated set of names and classifications for all of the source organisms represented in the INSDC." /><meta name="og:url" content="https://www.ncbi.nlm.nih.gov/books/NBK53758/" /><meta name="og:site_name" content="NCBI Bookshelf" /><meta name="og:image" content="https://www.ncbi.nlm.nih.gov/corehtml/pmc/pmcgifs/bookshelf/thumbs/th-helptaxonomy-lrg.png" /><meta name="twitter:card" content="summary" /><meta name="twitter:site" content="@ncbibooks" /><meta name="bk-non-canon-loc" content="/books/n/helptaxonomy/taxonomyqs/" /><link rel="canonical" href="https://www.ncbi.nlm.nih.gov/books/NBK53758/" /><link rel="stylesheet" href="/corehtml/pmc/css/figpopup.css" type="text/css" media="screen" /><link rel="stylesheet" href="/corehtml/pmc/css/bookshelf/2.26/css/books.min.css" type="text/css" /><link rel="stylesheet" href="/corehtml/pmc/css/bookshelf/2.26/css/books_print.min.css" type="text/css" media="print" /><style type="text/css">p a.figpopup{display:inline !important} .bk_tt {font-family: monospace} .first-line-outdent .bk_ref {display: inline} .body-content h2, .body-content .h2 {border-bottom: 1px solid #97B0C8} .body-content h2.inline {border-bottom: none} a.page-toc-label , .jig-ncbismoothscroll a {text-decoration:none;border:0 !important} .temp-labeled-list .graphic {display:inline-block !important} .temp-labeled-list img{width:100%}</style><script type="text/javascript" src="/corehtml/pmc/js/jquery.hoverIntent.min.js"> </script><script type="text/javascript" src="/corehtml/pmc/js/common.min.js?_=3.18"> </script><script type="text/javascript" src="/corehtml/pmc/js/large-obj-scrollbars.min.js"> </script><script type="text/javascript">window.name="mainwindow";</script><script type="text/javascript" src="/corehtml/pmc/js/bookshelf/2.26/book-toc.min.js"> </script><script type="text/javascript" src="/corehtml/pmc/js/bookshelf/2.26/books.min.js"> </script><meta name="book-collection" content="helpcollect" />
<!-- Page meta end -->
<link rel="shortcut icon" href="//www.ncbi.nlm.nih.gov/favicon.ico" /><meta name="ncbi_phid" content="CE8CBB137D9FF3E100000000009D0088.m_12" />
<meta name='referrer' content='origin-when-cross-origin'/><link type="text/css" rel="stylesheet" href="//static.pubmed.gov/portal/portal3rc.fcgi/4216699/css/3852956/3985586/3808861/4121862/3974050/3917732/251717/4216701/14534/45193/4113719/3849091/3984811/3751656/4033350/3840896/3577051/3852958/4008682/4207974/4206132/4062871/12930/3964959/3854974/36029/4128070/9685/3549676/3609192/3609193/3609213/3395586.css" /><link type="text/css" rel="stylesheet" href="//static.pubmed.gov/portal/portal3rc.fcgi/4216699/css/3411343/3882866.css" media="print" /></head>
<body class="book-part">
<div class="grid">
<div class="col twelve_col nomargin shadow">
<!-- System messages like service outage or JS required; this is handled by the TemplateResources portlet -->
<div class="sysmessages">
<noscript>
<p class="nojs">
<strong>Warning:</strong>
The NCBI web site requires JavaScript to function.
<a href="/guide/browsers/#enablejs" title="Learn how to enable JavaScript" target="_blank">more...</a>
</p>
</noscript>
</div>
<!--/.sysmessage-->
<div class="wrap">
<div class="page">
<div class="top">
<div id="universal_header">
<section class="usa-banner">
<div class="usa-accordion">
<header class="usa-banner-header">
<div class="usa-grid usa-banner-inner">
<img src="https://www.ncbi.nlm.nih.gov/coreutils/uswds/img/favicons/favicon-57.png" alt="U.S. flag" />
<p>An official website of the United States government</p>
<button class="non-usa-accordion-button usa-banner-button" aria-expanded="false" aria-controls="gov-banner-top" type="button">
<span class="usa-banner-button-text">Here's how you know</span>
</button>
</div>
</header>
<div class="usa-banner-content usa-grid usa-accordion-content" id="gov-banner-top" aria-hidden="true">
<div class="usa-banner-guidance-gov usa-width-one-half">
<img class="usa-banner-icon usa-media_block-img" src="https://www.ncbi.nlm.nih.gov/coreutils/uswds/img/icon-dot-gov.svg" alt="Dot gov" />
<div class="usa-media_block-body">
<p>
<strong>The .gov means it's official.</strong>
<br />
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you're on a federal
government site.
</p>
</div>
</div>
<div class="usa-banner-guidance-ssl usa-width-one-half">
<img class="usa-banner-icon usa-media_block-img" src="https://www.ncbi.nlm.nih.gov/coreutils/uswds/img/icon-https.svg" alt="Https" />
<div class="usa-media_block-body">
<p>
<strong>The site is secure.</strong>
<br />
The <strong>https://</strong> ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
</p>
</div>
</div>
</div>
</div>
</section>
<div class="usa-overlay"></div>
<header class="ncbi-header" role="banner" data-section="Header">
<div class="usa-grid">
<div class="usa-width-one-whole">
<div class="ncbi-header__logo">
<a href="/" class="logo" aria-label="NCBI Logo" data-ga-action="click_image" data-ga-label="NIH NLM Logo">
<img src="https://www.ncbi.nlm.nih.gov/coreutils/nwds/img/logos/AgencyLogo.svg" alt="NIH NLM Logo" />
</a>
</div>
<div class="ncbi-header__account">
<a id="account_login" href="https://account.ncbi.nlm.nih.gov" class="usa-button header-button" style="display:none" data-ga-action="open_menu" data-ga-label="account_menu">Log in</a>
<button id="account_info" class="header-button" style="display:none" aria-controls="account_popup" type="button">
<span class="fa fa-user" aria-hidden="true">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="20px" height="20px">
<g style="fill: #fff">
<ellipse cx="12" cy="8" rx="5" ry="6"></ellipse>
<path d="M21.8,19.1c-0.9-1.8-2.6-3.3-4.8-4.2c-0.6-0.2-1.3-0.2-1.8,0.1c-1,0.6-2,0.9-3.2,0.9s-2.2-0.3-3.2-0.9 C8.3,14.8,7.6,14.7,7,15c-2.2,0.9-3.9,2.4-4.8,4.2C1.5,20.5,2.6,22,4.1,22h15.8C21.4,22,22.5,20.5,21.8,19.1z"></path>
</g>
</svg>
</span>
<span class="username desktop-only" aria-hidden="true" id="uname_short"></span>
<span class="sr-only">Show account info</span>
</button>
</div>
<div class="ncbi-popup-anchor">
<div class="ncbi-popup account-popup" id="account_popup" aria-hidden="true">
<div class="ncbi-popup-head">
<button class="ncbi-close-button" data-ga-action="close_menu" data-ga-label="account_menu" type="button">
<span class="fa fa-times">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 48 48" width="24px" height="24px">
<path d="M38 12.83l-2.83-2.83-11.17 11.17-11.17-11.17-2.83 2.83 11.17 11.17-11.17 11.17 2.83 2.83 11.17-11.17 11.17 11.17 2.83-2.83-11.17-11.17z"></path>
</svg>
</span>
<span class="usa-sr-only">Close</span></button>
<h4>Account</h4>
</div>
<div class="account-user-info">
Logged in as:<br />
<b><span class="username" id="uname_long">username</span></b>
</div>
<div class="account-links">
<ul class="usa-unstyled-list">
<li><a id="account_myncbi" href="/myncbi/" class="set-base-url" data-ga-action="click_menu_item" data-ga-label="account_myncbi">Dashboard</a></li>
<li><a id="account_pubs" href="/myncbi/collections/bibliography/" class="set-base-url" data-ga-action="click_menu_item" data-ga-label="account_pubs">Publications</a></li>
<li><a id="account_settings" href="/account/settings/" class="set-base-url" data-ga-action="click_menu_item" data-ga-label="account_settings">Account settings</a></li>
<li><a id="account_logout" href="/account/signout/" class="set-base-url" data-ga-action="click_menu_item" data-ga-label="account_logout">Log out</a></li>
</ul>
</div>
</div>
</div>
</div>
</div>
</header>
<div role="navigation" aria-label="access keys">
<a id="nws_header_accesskey_0" href="https://www.ncbi.nlm.nih.gov/guide/browsers/#ncbi_accesskeys" class="usa-sr-only" accesskey="0" tabindex="-1">Access keys</a>
<a id="nws_header_accesskey_1" href="https://www.ncbi.nlm.nih.gov" class="usa-sr-only" accesskey="1" tabindex="-1">NCBI Homepage</a>
<a id="nws_header_accesskey_2" href="/myncbi/" class="set-base-url usa-sr-only" accesskey="2" tabindex="-1">MyNCBI Homepage</a>
<a id="nws_header_accesskey_3" href="#maincontent" class="usa-sr-only" accesskey="3" tabindex="-1">Main Content</a>
<a id="nws_header_accesskey_4" href="#" class="usa-sr-only" accesskey="4" tabindex="-1">Main Navigation</a>
</div>
<section data-section="Alerts">
<div class="ncbi-alerts-placeholder"></div>
</section>
</div>
<div class="header">
<div class="res_logo"><h1 class="res_name"><a href="/books/" title="Bookshelf home">Bookshelf</a></h1><h2 class="res_tagline"></h2></div>
<div class="search"><form method="get" action="/books/"><div class="search_form"><label for="database" class="offscreen_noflow">Search database</label><select id="database"><optgroup label="Recent"><option value="books" selected="selected" data-ac_dict="bookshelf-search">Books</option><option value="snp">SNP</option><option value="nuccore">Nucleotide</option><option value="pmc" class="last">PMC</option></optgroup><optgroup label="All"><option value="gquery">All Databases</option><option value="assembly">Assembly</option><option value="biocollections">Biocollections</option><option value="bioproject">BioProject</option><option value="biosample">BioSample</option><option value="books" data-ac_dict="bookshelf-search">Books</option><option value="clinvar">ClinVar</option><option value="cdd">Conserved Domains</option><option value="gap">dbGaP</option><option value="dbvar">dbVar</option><option value="gene">Gene</option><option value="genome">Genome</option><option value="gds">GEO DataSets</option><option value="geoprofiles">GEO Profiles</option><option value="gtr">GTR</option><option value="ipg">Identical Protein Groups</option><option value="medgen">MedGen</option><option value="mesh">MeSH</option><option value="nlmcatalog">NLM Catalog</option><option value="nuccore">Nucleotide</option><option value="omim">OMIM</option><option value="pmc">PMC</option><option value="protein">Protein</option><option value="proteinclusters">Protein Clusters</option><option value="protfam">Protein Family Models</option><option value="pcassay">PubChem BioAssay</option><option value="pccompound">PubChem Compound</option><option value="pcsubstance">PubChem Substance</option><option value="pubmed">PubMed</option><option value="snp">SNP</option><option value="sra">SRA</option><option value="structure">Structure</option><option value="taxonomy">Taxonomy</option><option value="toolkit">ToolKit</option><option value="toolkitall">ToolKitAll</option><option value="toolkitbookgh">ToolKitBookgh</option></optgroup></select><div class="nowrap"><label for="term" class="offscreen_noflow" accesskey="/">Search term</label><div class="nowrap"><input type="text" name="term" id="term" title="Search Books. Use up and down arrows to choose an item from the autocomplete." value="" class="jig-ncbiclearbutton jig-ncbiautocomplete" data-jigconfig="dictionary:'bookshelf-search',disableUrl:'NcbiSearchBarAutoComplCtrl'" autocomplete="off" data-sbconfig="ds:'no',pjs:'no',afs:'no'" /></div><button id="search" type="submit" class="button_search nowrap" cmd="go">Search</button></div></div></form><ul class="searchlinks inline_list"><li>
<a href="/books/browse/">Browse Titles</a>
</li><li>
<a href="/books/advanced/">Advanced</a>
</li><li class="help">
<a href="/books/NBK3833/">Help</a>
</li><li class="disclaimer">
<a target="_blank" data-ga-category="literature_resources" data-ga-action="link_click" data-ga-label="disclaimer_link" href="https://www.ncbi.nlm.nih.gov/books/about/disclaimer/">Disclaimer</a>
</li></ul></div>
</div>
<!--<component id="Page" label="headcontent"/>-->
</div>
<div class="content">
<!-- site messages -->
<!-- Custom content 1 -->
<div class="col1">
</div>
<div class="container">
<div id="maincontent" class="content eight_col col">
<!-- Custom content in the left column above book nav -->
<div class="col2">
</div>
<!-- Book content -->
<!-- Custom content between navigation and content -->
<div class="col3">
</div>
<div class="document">
<div class="pre-content"><div><div class="bk_prnt"><p class="small">NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.</p><p>Taxonomy Help [Internet]. Bethesda (MD): National Center for Biotechnology Information (US); 2011-. </p></div><div class="iconblock clearfix whole_rhythm no_top_margin bk_noprnt"><a class="img_link icnblk_img" title="Table of Contents Page" href="/books/n/helptaxonomy/"><img class="source-thumb" src="/corehtml/pmc/pmcgifs/bookshelf/thumbs/th-helptaxonomy-lrg.png" alt="Cover of Taxonomy Help" height="100px" width="80px" /></a><div class="icnblk_cntnt eight_col"><h2>Taxonomy Help [Internet].</h2><a data-jig="ncbitoggler" href="#__NBK53758_dtls__">Show details</a><div style="display:none" class="ui-widget" id="__NBK53758_dtls__"><div>Bethesda (MD): <a href="https://www.ncbi.nlm.nih.gov/" ref="pagearea=page-banner&amp;targetsite=external&amp;targetcat=link&amp;targettype=publisher">National Center for Biotechnology Information (US)</a>; 2011-.</div></div><div class="half_rhythm"><ul class="inline_list"><li style="margin-right:1em"><a class="bk_cntns" href="/books/n/helptaxonomy/">Contents</a></li></ul></div><div class="bk_noprnt"><form method="get" action="/books/n/helptaxonomy/" id="bk_srch"><div class="bk_search"><label for="bk_term" class="offscreen_noflow">Search term</label><input type="text" title="Search this book" id="bk_term" name="term" value="" data-jig="ncbiclearbutton" /> <input type="submit" class="jig-ncbibutton" value="Search this book" submit="false" style="padding: 0.1em 0.4em;" /></div></form></div></div><div class="icnblk_cntnt two_col"><div class="pagination bk_noprnt"><a class="active page_link prev" href="/books/n/helptaxonomy/" title="Previous page in this title">&lt; Prev</a><a class="active page_link next" href="/books/n/helptaxonomy/TaxonomyFaq/" title="Next page in this title">Next &gt;</a></div></div></div></div></div>
<div class="main-content lit-style" itemscope="itemscope" itemtype="http://schema.org/CreativeWork"><div class="meta-content fm-sec"><h1 id="_NBK53758_"><span class="title" itemprop="name">NCBI Taxonomy</span></h1><p class="contrib-group"><span itemprop="author">Conrad Schoch</span>.</p><a data-jig="ncbitoggler" href="#__NBK53758_ai__" style="border:0;text-decoration:none">Author Information and Affiliations</a><div style="display:none" class="ui-widget" id="__NBK53758_ai__"><div class="contrib half_rhythm"><span itemprop="author">Conrad Schoch</span><div class="affiliation small">NCBI<div><span class="email-label">Email: </span><a href="mailto:dev@null" data-email="vog.hin.mln.ibcn@2hcohcs" class="oemail">vog.hin.mln.ibcn@2hcohcs</a></div></div></div></div><p class="small">Created: <span itemprop="datePublished">April 7, 2011</span>; Last Update: <span itemprop="dateModified">February 11, 2020</span>.</p><p><em>Estimated reading time: 11 minutes</em></p></div><div class="jig-ncbiinpagenav body-content whole_rhythm" data-jigconfig="allHeadingLevels: ['h2'],smoothScroll: false" itemprop="text"><div id="taxonomyqs.Overview"><h2 id="_taxonomyqs_Overview_">Overview</h2><p>The National Center for Biotechnology Information (NCBI) Taxonomy includes organism names and classifications for every sequence in the nucleotide and protein sequence databases of the International Nucleotide Sequence Database Collaboration (INSDC). It provides a framework for clustering elements within other domains of NCBI web pages, for internal linking between domains of the Entrez system and for linking out to taxon-specific external resources on the web and relevant publications. It is also the standard nomenclature and classification repository for the International Nucleotide Sequence Database Collaboration (INSDC) that comprises of GenBank, the European Molecular Biology Laboratory (EMBL) and DNA Data Bank of Japan (DDBJ). It consists of a curated set of names and classifications for all of the source organisms represented in the INSDC.</p><p>The NCBI taxonomy database contains a list of names that are determined to be nomenclaturally correct or valid (as defined according to the different codes of nomenclature), classified in an approximately phylogenetic hierarchy (depending on the level of knowledge regarding phylogenetic relationships of a given group) as well as a number of names that exist outside the jurisdiction of the codes. That is, it focuses on nomenclature and systematics, rather than documenting the description of taxa. It requires a curator to select a current name out of all possible names for a specific taxon. This is done by a specialist at the NCBI Taxonomy database, relying on published taxonomic data and external expert opinion. This single, current name are indicated on all INSDC records.</p></div><div id="taxonomyqs.A_brief_history"><h2 id="_taxonomyqs_A_brief_history_">A brief history</h2><p>An early version of the NCBI Taxonomy in 1991 was included in the first version of Entrez, the search and retrieval system for NCBI&#x02019;s linked databases. This was the first system to link nucleotides and proteins from numerous disparate sources with different taxonomic classification systems. In 1996 the first version of NCBI Taxonomy Web Browser was presented to the public and the INSDC decided on its annual meeting to utilize the NCBI Taxonomy as the only source for taxonomic classification to maintain consistency among databases. This included the decision that all issues regarding nomenclature and classification would be resolved prior to the public release of any sequence data. INSDC partners now send any requests for new names (taxonomy &#x0201c;consults&#x0201d;) to NCBI Taxonomy curators before final data release. Consequently, the NCBI taxonomy pages only display taxa that are linked to public sequence entries.</p></div><div id="taxonomyqs.Codes_of_Nomenclature"><h2 id="_taxonomyqs_Codes_of_Nomenclature_">Codes of Nomenclature</h2><p>NCBI Taxonomy distinguishes between <b>formal</b> and <b>informal</b> names. Formal names are declared based on rules laid down in four relevant codes of nomenclature (although other codes do exist). These are the International Code of Nomenclature for algae, fungi, and plants (ICNafp), the International Code of Nomenclature of Prokaryotes (ICNP) and the International Code of Zoological Nomenclature (ICZN). The viruses are governed by the International Code of Virus Classification and Nomenclature (ICVCN, also referred to as the ICTV Code). Informal names follow internal rules that are dictated by practical considerations outside of the Codes. For example, names lacking species epithets are commonly applied to GenBank records.</p></div><div id="taxonomyqs.Treatment_of_Type_Material_in"><h2 id="_taxonomyqs_Treatment_of_Type_Material_in_">Treatment of Type Material in NCBI Taxonomy</h2><p>A major change in database curation over the last decade was to document and track data related to the standard references for taxonomy: type strains and specimens. The word &#x02018;type&#x02019; forms part of many compound terms used by taxonomists. In all the above-mentioned codes one or more types is designated as an objective standard to fix the scientific name of the species or infraspecies (i. e. subspecies, variety or forma). The type of a species or infraspecies (taxon) is designated when the new taxon is described and illustrates the trait(s) that distinguish the new taxon from all other comparable taxa. Viruses rely on lists of names approved by the International Committee on Taxonomy of Viruses (ICTV) and their usage of exemplars, focused on sequence accessions do not apply.</p><p>Under the ICNafp and ICNP, types are never living, and usually consist of dried or pickled specimens or physiologically inactivated cultures. Prokaryotic types (Bacteria and Archaea) are always living cultures (type strains). The most common types encountered, as well as certain non-nomenclatural terms, are listed below. Types may be indicated by collector name and number plus institution code where the specimen is deposited, and/or institution accession or barcode number. We list the abbreviations of the nomenclatural codes that use them in parentheses (see above).</p><ul><li class="half_rhythm"><div><b>Type material</b> (not designated in any code). This is an internal term to NCBI Taxonomy, and if not further designated, refers to specimens or cultures where the type of type is unknown or unspecified.</div></li><li class="half_rhythm"><div><b>Holotype</b> (ICNafp, ICNP). is the most important. There is only one holotype, usually a single specimen, and it is the &#x02018;name-bearer&#x02019; of the described taxon. It serves as the standard to which all subsequent examples of the described taxon are compared. The equivalent term we use for prokaryotes is type strain (ICNP) and there can be multiple co-identical type strains, cultured from a single source.</div></li><li class="half_rhythm"><div><b>Neotype</b> (ICNafp, ICNP, ICZN). If the holotype is lost or destroyed, a neotype specimen is designated from a collection considered to be representative of the original holotype. There is only one neotype. The equivalent term we use for prokaryotes is neotype strain (ICNP) with multiple neotype strains possible when cultured from a single source.</div></li><li class="half_rhythm"><div><b>Isotype</b> (ICNafp). Under the ICNafp one or more duplicate specimens from the holotype collection can be deposited in other institutions. Usually the collection number is the same as the holotype, but the institution code has to be different. Iso- can be appended to other kinds of types to indicate duplicates, e.g., isosyntype, etc. Isotype is not a formally accepted term in the ICZN.</div></li></ul><p>The next set of types are considered of lower nomenclatural importance, because they are derived from specimens that act to inform and expand the concept of the preceding set of types and will generally be different genetically, although still potentially closely related.</p><ul><li class="half_rhythm"><div><b>Paratype</b> (ICNafp, ICZN). One or more additional specimens chosen to further illustrate traits in the described taxon.</div></li><li class="half_rhythm"><div><b>Epitype</b> (ICNafp): In botanical nomenclature only, a type designated to expand on the original holotype concept. There should be only one epitype.</div></li><li class="half_rhythm"><div><b>Culture from</b>
<b>type</b> (ICNafp): Also, sometimes designated ex-type, e.g., ex-holotype, etc. There can be multiple of these. The types of cultivable, microbial eukaryotes must be inactivated and one or preferably more living cultures is extracted from the type and maintained in culture collections. Since these are living, they do not have formal status as type, but since they will often be the source of DNA sequence data they are annotated and indicated as type material.</div></li><li class="half_rhythm"><div><b>Reference material</b> or <b>reference strain</b> (not designated in any code): The reference material and reference strain qualifiers are internal GenBank terms used to capture any reference strain or material exclusively of types. These terms can include specimens or cultures that don&#x02019;t have nomenclatural standing but nevertheless could have name-bearing value. For example, Candidatus prokaryotic names, are names proposed for new species that have not been formally described by the ICNP will receive reference strain designations, since technically they do not possess types.</div></li></ul><p>Additional types are listed under the controlled vocabulary for the INSDC: <a href="http://www.insdc.org/controlled-vocabulary-typematerial-qualifer" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">http://www.insdc.org/controlled-vocabulary-typematerial-qualifer</a></p></div><div id="taxonomyqs.Data_Model"><h2 id="_taxonomyqs_Data_Model_">Data Model</h2><p>Each entry in the INSDC databases maps onto an entry in the NCBI Taxonomy database at the level of species or below (an exception is made for patent entries). Since October 2018 the NCBI Taxonomy has been migrated from an SQL server relational database to a system that incorporates a system of databases, focused around a central resource called <b>NameBank</b>. This provides a framework for data including additional information that is not public in NCBI Taxonomy and contextualizes it.</p><p>Each NCBI Taxonomy entry or <b>TaxNode</b> includes: a <b>primary</b>
<b>Name</b> with a number of <b>secondary names</b>. Each entry or node has a public stable, unique identifier, the taxonomy identifier (<b>TaxId</b>) as well as the presence of separate, stable unique name entity identififers (<b>NameIds)</b> which are not public and managed in <b>NameBank</b>.</p><p>Each <b>TaxNode</b> has the following:</p><dl class="temp-labeled-list"><dt>1.</dt><dd><p class="no_top_margin"><b>TaxId</b></p></dd></dl><p>This is shared by all names for a specific <b>TaxNode</b>. Each <b>TaxNode</b> has a stable, unique numerical identifier, the taxonomy identifier (<b>TaxId</b>). Each <b>TaxId</b> has a labelled <b>primary name</b> (a <b>formal</b> or <b>informal name</b>) which shows up on the NCBI records.</p><p>In publications this can be standardized as a <b>primary name</b> with its <b>TaxId</b> displayed as &#x0201c;NCBI:txid&#x0201d; followed by a number, e.g.</p><p><i>Homo sapiens</i> NCBI:txid9606</p><p>This information is also displayed in the <b>NCBI TaxBrowser</b>.</p><p>2. <b>NameBank Entity Id</b></p><p>NameBank includes several separate, stable and unique name entity identifiers for <b>secondary</b>
<b>names</b> and their properties, managed in <b>NameBank</b>. Formal <b>secondary names</b> under the NCBI system will consist of a Latin binomial (consisting of the genus name and species epithet) as well as its authority (the person(s) who described the species) and a year of its description. In the NCBI Taxonomy this is the <b>current name</b> for the TaxNode labelled as <i>Homo sapiens:</i></p><p><i>Homo sapiens</i> Linneaus, 1758 (with a NameBank Entity Id, which is not displayed publicly)</p><p><b>Relational terms</b> make it possible to indicate relationship between for <b>secondary</b>
<b>names</b> and <b>primary names</b>. For instance, the first name attached to a species description is indicated as the <b>basionym</b>. The currently accepted name is indicated as <b>current name</b> (which could also be the first name). These terms also differentiate between different synonyms: <b>heterotypic synonym</b> and <b>homotypic synonym</b>. Homotypic (or objective synonyms), are names based on the same type (see discussion of type material). Heterotypic (or subjective) synonyms are based on different types that were considered distinct taxa when they were first proposed, but subsequently considered to belong to the same taxon, documented in a publication or other authoritative source. The <b>relational terms</b>, specifying relationships between the different names are indicated in <a class="figpopup" href="/books/NBK53758/table/taxonomyqs.T.relational_terms_in_ncbi_ta/?report=objectonly" target="object" rid-figpopup="figtaxonomyqsTrelationaltermsinncbita" rid-ob="figobtaxonomyqsTrelationaltermsinncbita">Table 1</a>.</p><div id="taxonomyqs.T.relational_terms_in_ncbi_ta" class="table"><h3><span class="label">Table 1. </span></h3><div class="caption"><p>Relational terms in NCBI Taxonomy.</p></div><p class="large-table-link" style="display:none"><span class="right"><a href="/books/NBK53758/table/taxonomyqs.T.relational_terms_in_ncbi_ta/?report=objectonly" target="object">View in own window</a></span></p><div class="large_tbl" id="__taxonomyqs.T.relational_terms_in_ncbi_ta_lrgtbl__"><table><thead><tr><th id="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="col" rowspan="1" colspan="1" style="background-color:rgb(217,217,217);text-align:left;vertical-align:bottom;">Name category</th><th id="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" scope="col" rowspan="1" colspan="1" style="background-color:rgb(217,217,217);text-align:left;vertical-align:bottom;">Description</th><th id="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" scope="col" rowspan="1" colspan="1" style="background-color:rgb(217,217,217);text-align:left;vertical-align:bottom;">Number per TaxNode/TaxId</th></tr></thead><tbody><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>primary name</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">This is the designated label for the TaxNode</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">One per TaxNode</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1 hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2 hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" colspan="3" scope="col" rowspan="1" style="text-align:left;vertical-align:top;"><b>Formal relational terms (relying on definitions in the codes of nomenclature)</b></td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>current name</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">The current name chosen out of all synonyms for the TaxNode. Will often overlap with primary name (except in a few cases) or, more rarely, basionym.</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Up to one per TaxNode (where indicated)</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>basionym</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">The originally described name, attached to the type material</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Up to one per name (where indicated), one to more per TaxNode</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>homotypic synonym</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Names generated after the basionym (e.g. by moving it to a different genus), but sharing the same type</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">None to several per TaxNode</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>heterotypic synonym</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Names with a different basionym and type from those mentioned above</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">None to several per TaxNode</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1 hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2 hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" colspan="3" scope="col" rowspan="1" style="text-align:left;vertical-align:top;"><b>Informal relational terms, public</b></td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>acronym</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Mainly used for viruses</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">None to several per TaxNode</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>equivalent</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Used for informal names which a related but not synonyms</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">None to several per TaxNode</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>includes</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Used for informal names which forms subset of a name</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">None to several per TaxNode</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>in-part</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Used for formal names which forms subset of a name</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">None to several per TaxNode &#x02013; can be duplicate across TaxNodes</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>blast name</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Informal name for groups of organisms</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Up to one per TaxNode (where indicated)</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>common name</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Informal names in common usage &#x02013; these are not comprehensively added</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">None to several per TaxNode</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>genbank acronym</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Name type that ensures an acronym name type is displayed prominently in flat files</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Up to one per TaxNode but excluding other genbank name types (where indicated)</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>genbank synonym</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Name type that ensures a second synonym is displayed prominently in flat files</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Up to one per TaxNode but excluding other genbank name types (where indicated)</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>genbank common name</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Name type that ensures a vernacular name is displayed prominently in flat files</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Up to one per TaxNode but excluding other genbank name types (where indicated)</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1 hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2 hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" colspan="3" scope="col" rowspan="1" style="text-align:left;vertical-align:top;"><b>Informal relational terms, not public</b></td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>misspelling</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Used for searches only</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">None to several per TaxNode</td></tr><tr><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_1" scope="row" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;"><b>unpublished name</b></td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_2" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">Used for searches only</td><td headers="hd_h_taxonomyqs.T.relational_terms_in_ncbi_ta_1_1_1_3" rowspan="1" colspan="1" style="text-align:left;vertical-align:top;">None to several per TaxNode</td></tr></tbody></table></div></div><p>Importantly, it should be noted that taxonomic information in the NCBI Taxonomy is not complete and several entries will only contain a primary name and current name. This reflect changes where minimal information was available when an entry was first made. Where additional information becomes available it is added to expand existing entries.</p></div><div id="taxonomyqs.Access"><h2 id="_taxonomyqs_Access_">Access</h2><p>The NCBI Taxonomy can be viewed and interacted with in three main ways.</p><dl class="temp-labeled-list"><dt>1.</dt><dd><p class="no_top_margin">Under the <b>NCBI Taxonomy Browser</b> two different kinds of web pages are supported. Hierarchy pages present the taxonomic classification, while taxon-specific pages summarize all of the information associated with a particular taxonomic entry. By default, the hierarchy displays three levels in the classification, but this can be changed (zero levels display the taxon-specific page). The hierarchy pages are also customized to display hotlinked counts of entries in other Entrez databases. Taxon specific pages will display the names and their relational terms associated with that entry (except for misspellings and unpublished names). The lineage can display a full or abbreviated classification. In addition to this, manually curated information is displayed as well. This includes type material and comments annotated by the taxonomic curators as well as relevant literature and type material information, with hotlinks as appropriate. An Entrez records table shows links to other Entrez databases, including links to records from type material, when they are available and annotated. At the bottom of the taxon specific pages additional layered information sets are found. For relevant organisms this can include <b>Genome information</b> with links to resource information in other databases. Another set of links are <b>External Information Resources</b> or <b>NCBI LinkOut</b>. This provides outside groups the ability to maintain links to externally curated resources after submitting information for their web-accessible resources (https://www.ncbi.nlm.nih.gov/projects/linkout/). Another block below this will display the modifiers such as <b>strain</b>, <b>isolate</b> or <b>culture collection</b> associated with the organism in GenBank sequence entries. Finally, additional search capabilities are supported in the <b>Taxonomy Browser</b> such as a wild card search.</p></dd><dt>2.</dt><dd><p class="no_top_margin"><b>Taxonomy Entrez</b> supports Boolean queries that includes search fields common across all Entrez databases. This is a uniform indexing, search, and retrieval engine for names. It differs from the other Entrez databases in that the default search field is [all names] instead of [all terms] &#x02013; unless you specify an explicit search field, <b>Taxonomy Entrez</b> assumes that you are searching with a name (or a <b>TaxId</b>). Each entry in the <b>Taxonomy Entrez</b> results represents a taxon and is identified by its <b>primary name</b>. The <b>primary name</b> for a taxon may be either formal (e.g. <i>Homo sapiens</i>) or informal (e.g. <i>Homo</i> sp. Altai, or uncultured fungus). Taxa above the species level may also be either formal (e.g. the order Mammalia) or informal (e.g. the clade node eudicotyledons). In addition, each taxon may be associated with <b>secondary names</b> with several relational terms &#x02013; homotypic synonyms, basionyms, misspellings, common names and so on.</p></dd></dl><p>Boolean queries can be used in Entrez to answer many questions. For example, how many amphibian taxa have appeared in Entrez for the first time this year? As with any Entrez query, it is often useful to set up &#x0201c;what&#x02019;s new&#x0201d; email updates in MyNCBI for queries of interest. Note: the &#x02018;specified&#x02019; property flags formal names at and below the species level and the &#x02018;has type material&#x02019; filter will return all names with type material annotated, whether it links to records with this annotation or not.</p><p><a href="/sites/entrez?db=taxonomy&#x00026;term=Amphibia+%5Bsubtree%5D+AND+specified+%5Bprop%5D" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Amphibia [subtree] AND specified [prop]</a></p><p><a href="/sites/entrez?db=taxonomy&#x00026;term=Amphibia+%5Bsubtree%5D+AND+2019+%5Bdate%5D" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Amphibia [subtree] AND 2019 [date]</a></p><p><a href="/sites/entrez?db=taxonomy&#x00026;term=Amphibia+%5Bsubtree%5D+AND+2019/12/15:2020/01/15+%5Bdate%5D" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Amphibia [subtree] AND 2019/12/15:2020/01/15 [date]</a></p><p><a href="/sites/entrez?db=taxonomy&#x00026;term=Amphibia+%5Bsubtree%5D+AND+2020+%5Bdate%5D+AND+species%5Brank%5D" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Amphibia [subtree] AND 2020 [date] AND species [rank]</a></p><p><a href="/sites/entrez?db=taxonomy&#x00026;term=Amphibia+%5Bsubtree%5D+AND+2020+%5Bdate%5D+AND+species%5Brank%5D+AND+specified+%5Bprop%5D" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Amphibia [subtree] AND 2020 [date] AND species [rank] AND specified [prop]</a></p><p><a href="/sites/entrez?db=taxonomy&#x00026;term=Amphibia+%5Bsubtree%5D+AND+2020+%5Bdate%5D+AND+species%5Brank%5D+NOT+specified+%5Bprop%5D" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Amphibia [subtree] AND 2020 [date] AND species [rank] NOT specified [prop]</a></p><p><a href="https://www.ncbi.nlm.nih.gov/taxonomy/?term=Amphibia+%5Bsubtree%5D+AND+has+type+material%5Bfilter%5D" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Amphibia [subtree] AND has type material[filter]</a></p><p>3. A third option is the full text files of the complete database that gets updated and deposited every hour at the <b>Taxonomy FTP</b> site as taxdump files. There is now also a second version of the FTP taxdump files. The new version includes taxonomic lineages of taxa and information on type material. The most important files in both sets of FTP files are nodes.dmp (which maps <b>TaxIds</b> to their parent <b>TaxIds</b>) and names.dmp (which maps names to <b>TaxIds</b>). Other files in both sets are delnodes.dmp which lists <b>TaxNodes</b> that have been deleted from the database, as well as <b>TaxNodes</b> that were once public but are no longer linked to any public sequence entries. Also, merged.dmp maps secondary <b>TaxIds</b> onto primary <b>TaxIds</b> for taxa that have been synonymized in the database. There is now also a second version of the FTP taxdump files. The new version includes files with differently formatted taxonomic lineages, information on type material and host information (<b>typematerial.dmp</b>, <b>typeoftype.dmp</b>, <b>rankedlineage.dmp</b>, <b>fullnamelineage.dmp</b>, <b>taxidlineage.dmp</b>, and <b>host.dmp</b>). Details are in the readme files.</p><p><b><u>Links to all three options are shown below:</u></b></p><dl class="temp-labeled-list"><dt>1.</dt><dd><p class="no_top_margin"><a href="/taxonomy" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">http://www<wbr style="display:inline-block"></wbr>.ncbi.nlm.nih.gov/taxonomy</a></p></dd><dt>2.</dt><dd><p class="no_top_margin"><a href="/Taxonomy/Browser.wwwtax.cgi" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">http://www<wbr style="display:inline-block"></wbr>.ncbi.nlm.nih<wbr style="display:inline-block"></wbr>.gov/Taxonomy/Browser.wwwtax.cgi</a></p></dd><dt>3.</dt><dd><p class="no_top_margin"><a href="ftp://ftp.ncbi.nih.gov/pub/taxonomy" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=ftp">ftp://ftp<wbr style="display:inline-block"></wbr>.ncbi.nih.gov/pub/taxonomy</a> (previous unchanged version, still supported)</p></dd></dl><p><a href="ftp://ftp.ncbi.nlm.nih.gov/pub/taxonomy/new_taxdump/" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=ftp">ftp://ftp.ncbi.nlm.nih.gov/pub/taxonomy/new_taxdump/</a> (new version, recommended for usage, with extra options)</p></div><div id="taxonomyqs.Other_tools_for_NCBI_Taxonomy"><h2 id="_taxonomyqs_Other_tools_for_NCBI_Taxonomy_">Other tools for NCBI Taxonomy information</h2><ul><li class="half_rhythm"><div>The <b>name/id status report</b> can be found under Taxonomy Tools on the NCBI Taxonomy home page (<a href="https://www.ncbi.nlm.nih.gov/Taxonomy/TaxIdentifier/tax_identifier.cgi" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">https://www.ncbi.nlm.nih.gov/Taxonomy/TaxIdentifier/tax_identifier.cgi</a>). This allows the user to upload a list of names (or <b>TaxIds</b>) to get back a report on their status and if they are present, which is preferred scientific name is being used at NCBI. A command-line version of this function (taxident) is available in the NCBI C++ toolkit.</div></li><li class="half_rhythm"><div><b>SourceCheck</b> reads in a set of Genbank accessions and returns associated metadata anid is now available as a standalone tool: <a href="ftp://ftp.ncbi.nih.gov/toolbox/ncbi_tools/cmdline/" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=ftp">ftp://ftp.ncbi.nih.gov/toolbox/ncbi_tools/cmdline/</a></div></li><li class="half_rhythm"><div>The <b>Taxonomy Common Tree</b>: <a href="https://www.ncbi.nlm.nih.gov/Taxonomy/CommonTree/wwwcmt.cgi" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">https://www.ncbi.nlm.nih.gov/Taxonomy/CommonTree/wwwcmt.cgi</a></div></li><li class="half_rhythm"><div>A live summary of the numbers of <b>Taxonomy Statistics</b>, all public entries in the NCBI Taxonomy, broken down by user-defined taxonomic group, date, or rank is available: <a href="https://www.ncbi.nlm.nih.gov/Taxonomy/taxonomyhome.html/index.cgi?chapter=statistics" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">https://www.ncbi.nlm.nih.gov/Taxonomy/taxonomyhome.html/index.cgi?chapter=statistics</a></div></li><li class="half_rhythm"><div>The <b>NCBI Tree Viewer</b> (TV): <a href="https://www.ncbi.nlm.nih.gov/tools/treeviewer/" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">https://www.ncbi.nlm.nih.gov/tools/treeviewer/</a>. More capabilities are available in the <b>NCBI Genome Workbench</b>: <a href="https://www.ncbi.nlm.nih.gov/tools/gbench/" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">https://www.ncbi.nlm.nih.gov/tools/gbench/</a></div></li></ul><p>A complete set of NCBI tools can be found here: <a href="https://www.ncbi.nlm.nih.gov/guide/all/" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">https://www.ncbi.nlm.nih.gov/guide/all/</a></p></div><div id="taxonomyqs.Further_reading"><h2 id="_taxonomyqs_Further_reading_">Further reading</h2><p><a href="https://pubmed.ncbi.nlm.nih.gov/22139910/" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Federhen, S. (2012) The NCBI Taxonomy database. Nucleic Acids Research, 40, D136-D143.</a></p><p><a href="https://pubmed.ncbi.nlm.nih.gov/25398905" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Federhen, S. (2015) Type material in the NCBI Taxonomy Database. Nucleic Acids Research, 43, D1086-D1098.</a></p><p><a href="https://pubmed.ncbi.nlm.nih.gov/29792589" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Ciufo, S., Kannan, S., Sharma, S., et al. (2018) Using average nucleotide identity to improve taxonomic assignments in prokaryotic genomes at the NCBI. Int J Syst Evol Microbiol, 68, 2386-2392.</a></p><p><a href="https://pubmed.ncbi.nlm.nih.gov/29688360/" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">Sharma, S., Ciufo, S., Starchenko, E., et al. (2018) The NCBI BioCollections Database. Database : the journal of biological databases and curation, 2018, bay006.</a></p></div><div id="bk_toc_contnr"></div></div></div>
<div class="post-content"><div><div class="half_rhythm"><a href="/books/about/copyright/">Copyright Notice</a></div><div class="small"><span class="label">Bookshelf ID: NBK53758</span></div><div style="margin-top:2em" class="bk_noprnt"><a class="bk_cntns" href="/books/n/helptaxonomy/">Contents</a><div class="pagination bk_noprnt"><a class="active page_link prev" href="/books/n/helptaxonomy/" title="Previous page in this title">&lt; Prev</a><a class="active page_link next" href="/books/n/helptaxonomy/TaxonomyFaq/" title="Next page in this title">Next &gt;</a></div></div></div></div>
</div>
<!-- Custom content below content -->
<div class="col4">
</div>
<!-- Book content -->
<!-- Custom contetnt below bottom nav -->
<div class="col5">
</div>
</div>
<div id="rightcolumn" class="four_col col last">
<!-- Custom content above discovery portlets -->
<div class="col6">
<div id="ncbi_share_book"><a href="#" class="ncbi_share" data-ncbi_share_config="popup:false,shorten:true" ref="id=NBK53758&amp;db=books">Share</a></div>
</div>
<div xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"></div><div class="portlet"><div class="portlet_head"><div class="portlet_title"><h3><span>Views</span></h3></div><a name="Shutter" sid="1" href="#" class="portlet_shutter" title="Show/hide content" remembercollapsed="true" pgsec_name="PDF_download" id="Shutter"></a></div><div class="portlet_content"><ul xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="simple-list"><li><a href="/books/NBK53758/?report=reader">PubReader</a></li><li><a href="/books/NBK53758/?report=printable">Print View</a></li><li><a data-jig="ncbidialog" href="#_ncbi_dlg_citbx_NBK53758" data-jigconfig="width:400,modal:true">Cite this Page</a><div id="_ncbi_dlg_citbx_NBK53758" style="display:none" title="Cite this Page"><div class="bk_tt">Schoch C. NCBI Taxonomy. 2011 Apr 7 [Updated 2020 Feb 11]. In: Taxonomy Help [Internet]. Bethesda (MD): National Center for Biotechnology Information (US); 2011-. <span class="bk_cite_avail"></span></div></div></li><li><a href="/books/NBK53758/pdf/Bookshelf_NBK53758.pdf">PDF version of this page</a> (106K)</li><li><a href="/books/n/helptaxonomy/pdf/">PDF version of this title</a> (1.0M)</li></ul></div></div><div class="portlet"><div class="portlet_head"><div class="portlet_title"><h3><span>In this Page</span></h3></div><a name="Shutter" sid="1" href="#" class="portlet_shutter" title="Show/hide content" remembercollapsed="true" pgsec_name="page-toc" id="Shutter"></a></div><div class="portlet_content"><ul xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="simple-list"><li><a href="#taxonomyqs.Overview" ref="log$=inpage&amp;link_id=inpage">Overview</a></li><li><a href="#taxonomyqs.A_brief_history" ref="log$=inpage&amp;link_id=inpage">A brief history</a></li><li><a href="#taxonomyqs.Codes_of_Nomenclature" ref="log$=inpage&amp;link_id=inpage">Codes of Nomenclature</a></li><li><a href="#taxonomyqs.Treatment_of_Type_Material_in" ref="log$=inpage&amp;link_id=inpage">Treatment of Type Material in NCBI Taxonomy</a></li><li><a href="#taxonomyqs.Data_Model" ref="log$=inpage&amp;link_id=inpage">Data Model</a></li><li><a href="#taxonomyqs.Access" ref="log$=inpage&amp;link_id=inpage">Access</a></li><li><a href="#taxonomyqs.Other_tools_for_NCBI_Taxonomy" ref="log$=inpage&amp;link_id=inpage">Other tools for NCBI Taxonomy information</a></li><li><a href="#taxonomyqs.Further_reading" ref="log$=inpage&amp;link_id=inpage">Further reading</a></li></ul></div></div><div class="portlet"><div class="portlet_head"><div class="portlet_title"><h3><span>Other titles in this collection</span></h3></div><a name="Shutter" sid="1" href="#" class="portlet_shutter" title="Show/hide content" remembercollapsed="true" pgsec_name="source-links" id="Shutter"></a></div><div class="portlet_content"><ul xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="simple-list"><li><a href="/books/n/helpcollect/">NCBI Help Manual</a></li></ul></div></div><div class="portlet"><div class="portlet_head"><div class="portlet_title"><h3><span>Recent Activity</span></h3></div><a name="Shutter" sid="1" href="#" class="portlet_shutter" title="Show/hide content" remembercollapsed="true" pgsec_name="recent_activity" id="Shutter"></a></div><div class="portlet_content"><div xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" id="HTDisplay" class=""><div class="action"><a href="javascript:historyDisplayState('ClearHT')">Clear</a><a href="javascript:historyDisplayState('HTOff')" class="HTOn">Turn Off</a><a href="javascript:historyDisplayState('HTOn')" class="HTOff">Turn On</a></div><ul id="activity"><li class="ra_rcd ralinkpopper two_line"><a class="htb ralinkpopperctrl" ref="log$=activity&amp;linkpos=1" href="/portal/utils/pageresolver.fcgi?recordid=67da0a3f2f30673f7b0576c9">NCBI Taxonomy - Taxonomy Help</a><div class="ralinkpop offscreen_noflow">NCBI Taxonomy - Taxonomy Help<div class="brieflinkpopdesc"></div></div><div class="tertiary"></div></li><li class="ra_rcd ralinkpopper two_line"><a class="htb ralinkpopperctrl" ref="log$=activity&amp;linkpos=2" href="/portal/utils/pageresolver.fcgi?recordid=67da0a3ecde49f3df7f24b5b">Creating a Web Link to PubMed - Web Link Help</a><div class="ralinkpop offscreen_noflow">Creating a Web Link to PubMed - Web Link Help<div class="brieflinkpopdesc"></div></div><div class="tertiary"></div></li><li class="ra_rcd ralinkpopper two_line"><a class="htb ralinkpopperctrl" ref="log$=activity&amp;linkpos=3" href="/portal/utils/pageresolver.fcgi?recordid=67da0a3967c23b31e0b91465">SciENcv - My NCBI Help</a><div class="ralinkpop offscreen_noflow">SciENcv - My NCBI Help<div class="brieflinkpopdesc"></div></div><div class="tertiary"></div></li><li class="ra_qry two_line"><a class="htb" ref="log$=activity&amp;linkpos=4" href="/portal/utils/pageresolver.fcgi?recordid=67da0a28cde49f3df7f207ec">100 : 1000[SLEN] <span class="number">(341752994)</span></a><div class="tertiary">Nucleotide</div></li><li class="ra_qry two_line"><a class="htb" ref="log$=activity&amp;linkpos=5" href="/portal/utils/pageresolver.fcgi?recordid=67da0a1b84f3725e59300f5f">srcdb_ddbj/embl/genbank[Properties] <span class="number">(515776928)</span></a><div class="tertiary">Nucleotide</div></li></ul><p class="HTOn">Your browsing activity is empty.</p><p class="HTOff">Activity recording is turned off.</p><p id="turnOn" class="HTOff"><a href="javascript:historyDisplayState('HTOn')">Turn recording back on</a></p><a class="seemore" href="/sites/myncbi/recentactivity">See more...</a></div></div></div>
<!-- Custom content below discovery portlets -->
<div class="col7">
</div>
</div>
</div>
<!-- Custom content after all -->
<div class="col8">
</div>
<div class="col9">
</div>
<script type="text/javascript" src="/corehtml/pmc/js/jquery.scrollTo-1.4.2.js"></script>
<script type="text/javascript">
(function($){
$('.skiplink').each(function(i, item){
var href = $($(item).attr('href'));
href.attr('tabindex', '-1').addClass('skiptarget'); // ensure the target can receive focus
$(item).on('click', function(event){
event.preventDefault();
$.scrollTo(href, 0, {
onAfter: function(){
href.focus();
}
});
});
});
})(jQuery);
</script>
</div>
<div class="bottom">
<div id="NCBIFooter_dynamic">
<!--<component id="Breadcrumbs" label="breadcrumbs"/>
<component id="Breadcrumbs" label="helpdesk"/>-->
</div>
<div class="footer" id="footer">
<section class="icon-section">
<div id="icon-section-header" class="icon-section_header">Follow NCBI</div>
<div class="grid-container container">
<div class="icon-section_container">
<a class="footer-icon" id="footer_twitter" href="https://twitter.com/ncbi" aria-label="Twitter"><svg xmlns="http://www.w3.org/2000/svg" data-name="Layer 1" viewBox="0 0 300 300">
<defs>
<style>
.cls-11 {
fill: #737373;
}
</style>
</defs>
<title>Twitter</title>
<path class="cls-11" d="M250.11,105.48c-7,3.14-13,3.25-19.27.14,8.12-4.86,8.49-8.27,11.43-17.46a78.8,78.8,0,0,1-25,9.55,39.35,39.35,0,0,0-67,35.85,111.6,111.6,0,0,1-81-41.08A39.37,39.37,0,0,0,81.47,145a39.08,39.08,0,0,1-17.8-4.92c0,.17,0,.33,0,.5a39.32,39.32,0,0,0,31.53,38.54,39.26,39.26,0,0,1-17.75.68,39.37,39.37,0,0,0,36.72,27.3A79.07,79.07,0,0,1,56,223.34,111.31,111.31,0,0,0,116.22,241c72.3,0,111.83-59.9,111.83-111.84,0-1.71,0-3.4-.1-5.09C235.62,118.54,244.84,113.37,250.11,105.48Z">
</path>
</svg></a>
<a class="footer-icon" id="footer_facebook" href="https://www.facebook.com/ncbi.nlm" aria-label="Facebook"><svg xmlns="http://www.w3.org/2000/svg" data-name="Layer 1" viewBox="0 0 300 300">
<title>Facebook</title>
<path class="cls-11" d="M210.5,115.12H171.74V97.82c0-8.14,5.39-10,9.19-10h27.14V52l-39.32-.12c-35.66,0-42.42,26.68-42.42,43.77v19.48H99.09v36.32h27.24v109h45.41v-109h35Z">
</path>
</svg></a>
<a class="footer-icon" id="footer_linkedin" href="https://www.linkedin.com/company/ncbinlm" aria-label="LinkedIn"><svg xmlns="http://www.w3.org/2000/svg" data-name="Layer 1" viewBox="0 0 300 300">
<title>LinkedIn</title>
<path class="cls-11" d="M101.64,243.37H57.79v-114h43.85Zm-22-131.54h-.26c-13.25,0-21.82-10.36-21.82-21.76,0-11.65,8.84-21.15,22.33-21.15S101.7,78.72,102,90.38C102,101.77,93.4,111.83,79.63,111.83Zm100.93,52.61A17.54,17.54,0,0,0,163,182v61.39H119.18s.51-105.23,0-114H163v13a54.33,54.33,0,0,1,34.54-12.66c26,0,44.39,18.8,44.39,55.29v58.35H198.1V182A17.54,17.54,0,0,0,180.56,164.44Z">
</path>
</svg></a>
<a class="footer-icon" id="footer_github" href="https://github.com/ncbi" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" data-name="Layer 1" viewBox="0 0 300 300">
<defs>
<style>
.cls-11,
.cls-12 {
fill: #737373;
}
.cls-11 {
fill-rule: evenodd;
}
</style>
</defs>
<title>GitHub</title>
<path class="cls-11" d="M151.36,47.28a105.76,105.76,0,0,0-33.43,206.1c5.28,1,7.22-2.3,7.22-5.09,0-2.52-.09-10.85-.14-19.69-29.42,6.4-35.63-12.48-35.63-12.48-4.81-12.22-11.74-15.47-11.74-15.47-9.59-6.56.73-6.43.73-6.43,10.61.75,16.21,10.9,16.21,10.9,9.43,16.17,24.73,11.49,30.77,8.79,1-6.83,3.69-11.5,6.71-14.14C108.57,197.1,83.88,188,83.88,147.51a40.92,40.92,0,0,1,10.9-28.39c-1.1-2.66-4.72-13.42,1-28,0,0,8.88-2.84,29.09,10.84a100.26,100.26,0,0,1,53,0C198,88.3,206.9,91.14,206.9,91.14c5.76,14.56,2.14,25.32,1,28a40.87,40.87,0,0,1,10.89,28.39c0,40.62-24.74,49.56-48.29,52.18,3.79,3.28,7.17,9.71,7.17,19.58,0,14.15-.12,25.54-.12,29,0,2.82,1.9,6.11,7.26,5.07A105.76,105.76,0,0,0,151.36,47.28Z">
</path>
<path class="cls-12" d="M85.66,199.12c-.23.52-1.06.68-1.81.32s-1.2-1.06-.95-1.59,1.06-.69,1.82-.33,1.21,1.07.94,1.6Zm-1.3-1">
</path>
<path class="cls-12" d="M90,203.89c-.51.47-1.49.25-2.16-.49a1.61,1.61,0,0,1-.31-2.19c.52-.47,1.47-.25,2.17.49s.82,1.72.3,2.19Zm-1-1.08">
</path>
<path class="cls-12" d="M94.12,210c-.65.46-1.71,0-2.37-.91s-.64-2.07,0-2.52,1.7,0,2.36.89.65,2.08,0,2.54Zm0,0"></path>
<path class="cls-12" d="M99.83,215.87c-.58.64-1.82.47-2.72-.41s-1.18-2.06-.6-2.7,1.83-.46,2.74.41,1.2,2.07.58,2.7Zm0,0">
</path>
<path class="cls-12" d="M107.71,219.29c-.26.82-1.45,1.2-2.64.85s-2-1.34-1.74-2.17,1.44-1.23,2.65-.85,2,1.32,1.73,2.17Zm0,0">
</path>
<path class="cls-12" d="M116.36,219.92c0,.87-1,1.59-2.24,1.61s-2.29-.68-2.3-1.54,1-1.59,2.26-1.61,2.28.67,2.28,1.54Zm0,0">
</path>
<path class="cls-12" d="M124.42,218.55c.15.85-.73,1.72-2,1.95s-2.37-.3-2.52-1.14.73-1.75,2-2,2.37.29,2.53,1.16Zm0,0"></path>
</svg></a>
<a class="footer-icon" id="footer_blog" href="https://ncbiinsights.ncbi.nlm.nih.gov/" aria-label="Blog">
<svg xmlns="http://www.w3.org/2000/svg" id="Layer_1" data-name="Layer 1" viewBox="0 0 40 40">
<defs><style>.cls-1{fill:#737373;}</style></defs>
<title>NCBI Insights Blog</title>
<path class="cls-1" d="M14,30a4,4,0,1,1-4-4,4,4,0,0,1,4,4Zm11,3A19,19,0,0,0,7.05,15a1,1,0,0,0-1,1v3a1,1,0,0,0,.93,1A14,14,0,0,1,20,33.07,1,1,0,0,0,21,34h3a1,1,0,0,0,1-1Zm9,0A28,28,0,0,0,7,6,1,1,0,0,0,6,7v3a1,1,0,0,0,1,1A23,23,0,0,1,29,33a1,1,0,0,0,1,1h3A1,1,0,0,0,34,33Z"></path>
</svg>
</a>
</div>
</div>
</section>
<section class="container-fluid bg-primary">
<div class="container pt-5">
<div class="row mt-3">
<div class="col-lg-3 col-12">
<p><a class="text-white" href="https://www.nlm.nih.gov/socialmedia/index.html">Connect with NLM</a></p>
<ul class="list-inline social_media">
<li class="list-inline-item"><a href="https://twitter.com/NLM_NIH" aria-label="Twitter" target="_blank" rel="noopener noreferrer"><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" x="0px" y="0px" viewBox="0 0 249 249" style="enable-background:new 0 0 249 249;" xml:space="preserve">
<style type="text/css">
.st20 {
fill: #FFFFFF;
}
.st30 {
fill: none;
stroke: #FFFFFF;
stroke-width: 8;
stroke-miterlimit: 10;
}
</style>
<title>Twitter</title>
<g>
<g>
<g>
<path class="st20" d="M192.9,88.1c-5,2.2-9.2,2.3-13.6,0.1c5.7-3.4,6-5.8,8.1-12.3c-5.4,3.2-11.4,5.5-17.6,6.7 c-10.5-11.2-28.1-11.7-39.2-1.2c-7.2,6.8-10.2,16.9-8,26.5c-22.3-1.1-43.1-11.7-57.2-29C58,91.6,61.8,107.9,74,116 c-4.4-0.1-8.7-1.3-12.6-3.4c0,0.1,0,0.2,0,0.4c0,13.2,9.3,24.6,22.3,27.2c-4.1,1.1-8.4,1.3-12.5,0.5c3.6,11.3,14,19,25.9,19.3 c-11.6,9.1-26.4,13.2-41.1,11.5c12.7,8.1,27.4,12.5,42.5,12.5c51,0,78.9-42.2,78.9-78.9c0-1.2,0-2.4-0.1-3.6 C182.7,97.4,189.2,93.7,192.9,88.1z"></path>
</g>
</g>
<circle class="st30" cx="124.4" cy="128.8" r="108.2"></circle>
</g>
</svg></a></li>
<li class="list-inline-item"><a href="https://www.facebook.com/nationallibraryofmedicine" aria-label="Facebook" rel="noopener noreferrer" target="_blank">
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" x="0px" y="0px" viewBox="0 0 249 249" style="enable-background:new 0 0 249 249;" xml:space="preserve">
<style type="text/css">
.st10 {
fill: #FFFFFF;
}
.st110 {
fill: none;
stroke: #FFFFFF;
stroke-width: 8;
stroke-miterlimit: 10;
}
</style>
<title>Facebook</title>
<g>
<g>
<path class="st10" d="M159,99.1h-24V88.4c0-5,3.3-6.2,5.7-6.2h16.8V60l-24.4-0.1c-22.1,0-26.2,16.5-26.2,27.1v12.1H90v22.5h16.9 v67.5H135v-67.5h21.7L159,99.1z"></path>
</g>
</g>
<circle class="st110" cx="123.6" cy="123.2" r="108.2"></circle>
</svg>
</a></li>
<li class="list-inline-item"><a href="https://www.youtube.com/user/NLMNIH" aria-label="Youtube" target="_blank" rel="noopener noreferrer"><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" x="0px" y="0px" viewBox="0 0 249 249" style="enable-background:new 0 0 249 249;" xml:space="preserve">
<title>Youtube</title>
<style type="text/css">
.st4 {
fill: none;
stroke: #FFFFFF;
stroke-width: 8;
stroke-miterlimit: 10;
}
.st5 {
fill: #FFFFFF;
}
</style>
<circle class="st4" cx="124.2" cy="123.4" r="108.2"></circle>
<g transform="translate(0,-952.36218)">
<path class="st5" d="M88.4,1037.4c-10.4,0-18.7,8.3-18.7,18.7v40.1c0,10.4,8.3,18.7,18.7,18.7h72.1c10.4,0,18.7-8.3,18.7-18.7 v-40.1c0-10.4-8.3-18.7-18.7-18.7H88.4z M115.2,1058.8l29.4,17.4l-29.4,17.4V1058.8z"></path>
</g>
</svg></a></li>
</ul>
</div>
<div class="col-lg-3 col-12">
<p class="address_footer text-white">National Library of Medicine<br />
<a href="https://www.google.com/maps/place/8600+Rockville+Pike,+Bethesda,+MD+20894/@38.9959508,-77.101021,17z/data=!3m1!4b1!4m5!3m4!1s0x89b7c95e25765ddb:0x19156f88b27635b8!8m2!3d38.9959508!4d-77.0988323" class="text-white" target="_blank" rel="noopener noreferrer">8600 Rockville Pike<br />
Bethesda, MD 20894</a></p>
</div>
<div class="col-lg-3 col-12 centered-lg">
<p><a href="https://www.nlm.nih.gov/web_policies.html" class="text-white">Web Policies</a><br />
<a href="https://www.nih.gov/institutes-nih/nih-office-director/office-communications-public-liaison/freedom-information-act-office" class="text-white">FOIA</a><br />
<a href="https://www.hhs.gov/vulnerability-disclosure-policy/index.html" class="text-white" id="vdp">HHS Vulnerability Disclosure</a></p>
</div>
<div class="col-lg-3 col-12 centered-lg">
<p><a class="supportLink text-white" href="https://support.nlm.nih.gov/">Help</a><br />
<a href="https://www.nlm.nih.gov/accessibility.html" class="text-white">Accessibility</a><br />
<a href="https://www.nlm.nih.gov/careers/careers.html" class="text-white">Careers</a></p>
</div>
</div>
<div class="row">
<div class="col-lg-12 centered-lg">
<nav class="bottom-links">
<ul class="mt-3">
<li>
<a class="text-white" href="//www.nlm.nih.gov/">NLM</a>
</li>
<li>
<a class="text-white" href="https://www.nih.gov/">NIH</a>
</li>
<li>
<a class="text-white" href="https://www.hhs.gov/">HHS</a>
</li>
<li>
<a class="text-white" href="https://www.usa.gov/">USA.gov</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
</section>
<script type="text/javascript" src="/portal/portal3rc.fcgi/rlib/js/InstrumentOmnitureBaseJS/InstrumentNCBIConfigJS/InstrumentNCBIBaseJS/InstrumentPageStarterJS.js?v=1"> </script>
<script type="text/javascript" src="/portal/portal3rc.fcgi/static/js/hfjs2.js"> </script>
</div>
</div>
</div>
<!--/.page-->
</div>
<!--/.wrap-->
</div><!-- /.twelve_col -->
</div>
<!-- /.grid -->
<span class="PAFAppResources"></span>
<!-- BESelector tab -->
<noscript><img alt="statistics" src="/stat?jsdisabled=true&amp;ncbi_db=books&amp;ncbi_pdid=book-part&amp;ncbi_acc=NBK53758&amp;ncbi_domain=helptaxonomy&amp;ncbi_report=record&amp;ncbi_type=fulltext&amp;ncbi_objectid=&amp;ncbi_pcid=/NBK53758/&amp;ncbi_pagename=NCBI Taxonomy - Taxonomy Help - NCBI Bookshelf&amp;ncbi_bookparttype=chapter&amp;ncbi_app=bookshelf" /></noscript>
<!-- usually for JS scripts at page bottom -->
<!--<component id="PageFixtures" label="styles"></component>-->
<!-- CE8BC1E97D9F05E1_0182SID /projects/books/PBooks@9.11 portal105 v4.1.r689238 Tue, Oct 22 2024 16:10:51 -->
<span id="portal-csrf-token" style="display:none" data-token="CE8BC1E97D9F05E1_0182SID"></span>
<script type="text/javascript" src="//static.pubmed.gov/portal/portal3rc.fcgi/4216699/js/3879255/4121861/3501987/4008961/3893018/3821238/4062932/4209313/4212053/4076480/3921943/3400083/3426610.js" snapshot="books"></script></body>
</html>