26e75bcc08d44f024ac657e96ef829295411cb95
dschmelt
  Fri May 3 14:35:41 2019 -0700
Pushing changes including formatting, typo corrections, and composite track info #23131

diff --git src/hg/htdocs/FAQ/FAQlink.html src/hg/htdocs/FAQ/FAQlink.html
index 91c8788..ed4fe58 100755
--- src/hg/htdocs/FAQ/FAQlink.html
+++ src/hg/htdocs/FAQ/FAQlink.html
@@ -1,143 +1,151 @@
 <!DOCTYPE html>
 <!--#set var="TITLE" value="Genome Browser FAQ" -->
 <!--#set var="ROOT" value=".." -->
 
 <!-- Relative paths to support mirror sites with non-standard GB docs install -->
 <!--#include virtual="$ROOT/inc/gbPageStart.html" -->
 
 <h1>Frequently Asked Questions: Linking to the Genome Browser</h1>
 
 <h2>Topics</h2>
 
 <ul>
-<li><a href="#link1">Creating a custom URL to view specific tracks</a></li>
+<li><a href="#link1">Creating a sharable URL to view specific tracks</a></li>
 <li><a href="#link2">Linking to the Browser at a specific position</a></li>
 <li><a href="#link3">Linking to gene specific information</a></li>
-<li><a href="#trackViz">Changing Track Visibilites via URL</a></li>
+<li><a href="#trackViz">Changing Track Visibility via URL</a></li>
 <li><a href="#ctUrl">Adding Custom Tracks via URL</a></li>
 <li><a href="#hubUrl">Connection to a Track Hub via URL</a></li>
 <li><a href="../goldenPath/help/customTrack.html#optParams">Additional URL parameters</a></li>
 </ul>
 
 <a name="link1"></a>
-<h2>Creating a custom URL to view specific tracks</h2>
+<h2>Creating a sharable URL to view specific tracks</h2>
 <p> 
-The easiest way to save and share tracks via URL is by
+The easiest way to save and share tracks from the URL is by
 <a href="../cgi-bin/hgLogin" TARGET="_blank">logging in</a> to your Genome Browser account and
 creating a <a href="../goldenPath/help/hgSessionHelp.html">saved session</a>.
-Saved sessions are a versatile way to share data and may include native data, Custom Tracks, and
+Saved sessions are a versatile way to share data that may include native data, Custom Tracks, and
 Track Hubs.</p>
 <p>
-You will be able to save and restore Genome Browser sessions with the following formats:
-<pre>http://genome.ucsc.edu/s/<em>userName</em>/<em>sessionName</em></pre></p>
+You will be able to save and share Genome Browser sessions with the following format:
+<p><code>http://genome.ucsc.edu/s/<em>userName</em>/<em>sessionName</em></code></p></p>
 <p>
-Or if you prefer the modifiable, longer format URL, use this format:</p>
-<pre>http://genome.ucsc.edu/cgi-bin/hgTracks?hgS_doOtherUser=submit&hgS_otherUserName=[<em>UserName</em>]&hgS_otherUserSessionName=[<em>SessionName</em>]</pre>
+Or if you prefer the a modifiable, longer URL; use this format:</p>
+<p><code>http://genome.ucsc.edu/cgi-bin/hgTracks?hgS_doOtherUser=submit&hgS_otherUserName=[<em>UserName</em>]&hgS_otherUserSessionName=[<em>SessionName</em>]</code></p>
 <p>
 For instructions on creating a saved session, go to the 
 <a href="../goldenPath/help/hgSessionHelp.html#Create">Saved Session Help page</a>.</p>
 <p> 
-If you want to specify track settings in a URL directly, you can do so by naming the track and
-visibility option directly in the URL. Note that these track parameters do not work on the shorter
-session URLs. For example, the following URL parameters displays the hg38 genome database with the 
-Known Gene track in pack mode and the RefSeq Genes in full mode:
-<pre><code><a href="http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&knownGene=pack&refGene=full">http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&knownGene=pack&refGene=full</a></code></pre>
+If you want to specify track settings in a URL directly, please read the section on 
+<a href"#trackViz">changing track visibility via URL</a> for a complete description. 
+Note that these URL parameters do not work with the shorter session URLs. 
 
 <a name="link2"></a>
-<h2>Linking to a specific position in the Genome Browser</h2>
+<h2>Linking to the Browser at a specific position</h2>
 <p>
-You can link to a specific position in the Genome Browser using a URL with the <code>db=</code>
-and <code>position=</code> parameters:</p>
+You can link to a specific genome assembly and position in the Genome Browser using a URL with
+the <code>db=</code> and <code>position=</code> parameters:</p>
 <p><code>http://genome.ucsc.edu/cgi-bin/hgTracks?db=[<em>db</em>]&position=[<em>position</em>]</code></p>
 <p>
 Where:</p>
 <ul>
   <li>
   <code>db</code> - designates a specific genome assembly. For example, <code>db=hg19</code> 
-  refers to the Feb. 2009 human genome release. For a list of the db parameter values that 
+  refers to the Feb. 2009 human genome release. For a list of db parameter values that 
   correspond to UCSC assemblies, see the <a href="FAQreleases.html#release1">list of UCSC 
   releases</a>.</li>
-  <li><code>position</code> - can be any search value valid for the genome specified, including
+  <li><code>position</code> - can be any seach term for the genome specified, including
   a position range or a gene identifier. This often takes the form of
   <code>position=chr1:35000-40000</code>.</li>
 </ul>
 <p>The following link is an example of a URL that declares assembly and position:</p>
 <p><code><a href=../cgi-bin/hgTracks?db=hg19&position=chr1:35000-40000>http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg19&position=chr1:35000-40000</a></code></p>
 
 <a name="hgsid"></a>
 <h2>The <em>hgsid</em> parameter</h2>
-<p><code>hgsid=724184099_ZY6sql8XPIZcZx9b2RJm2aQBBZ78</code></p>
-
-<p>The hgsid is a temporary user ID that stores display setting and custom track information.
-Including it in any shared URLs is a privacy concern, and should be removed when 
+<p>The hgsid is a temporary user ID that stores setting and custom track information in the URL.
+Including it in any shared URLs is a privacy concern, and it should be removed when 
 constructing any links to the Genome Browser. Creating 
-<a href="../goldenPath/help/hgSessionHelp.html#Create">Saved Sessions</a> is a much safer way to
-share particular Genome Browser views.
+<a href="../goldenPath/help/hgSessionHelp.html#Create">Saved Sessions</a> is the recommended way to
+share Genome Browser information.
 </p>
 
+
 <a name="trackViz"></a>
 <h2>Setting Track Visibitlies via URL</h2>
 <p>
-You can control the visibility of tracks via the URL with the following parameters, 
-each linked by the &amp; sign, similar to previous commands. Here are a few commands you  can use
-to control track visibility. Note that <em>italic text</em> indicates a user variable and not
-a valid a option.</p>
+You can control the visibility of tracks from the URL with the following parameters, 
+each linked by the "&amp;" sign, similar to position commands. For the full list, please see the 
+<a href="../../goldenPath/help/customTrack.html#optParams" target ="_blank">optional URL 
+parameters</a> section of the Custom Tracks User's Guide. Note that <em>italic text</em> indicates
+a user choice, not a working example.</p>
 <ul>
 <li>hideTracks=1</li>
 <li><em>trackName</em>=hide|dense|pack|full</li>
 <li>textSize=<em>number</em></li>
-<li>ignoreCookie=1</li>
-<li>position=chr1:25000-30000</li>
-<li>position=<em>geneSymbol</em>&singleSearch=knownCanonical</li>
 </ul>
 <p>
-For example, you can use the following command to only show the knownGene track:</p>
-<pre><a href=../cgi-bin/hgTracks?db=hg38&hideTracks=1&knownGene=pack>http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&hideTracks=1&knownGene=pack</a></pre>
-<p>You can use the following command to go to a particular position: </p>
-<pre><a href=../cgi-bin/hgTracks?db=hg19&position=chr1:25000-30000>http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg19&position=chr1:25000-30000</a></pre>
-<p>You can use the following command to go to a particular gene:</p>
-<pre><a href=../cgi-bin/hgTracks?db=hg38&position=KRAS&singleSearch=knownCanonical>http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&position=KRAS&singleSearch=knownCanonical</a></pre>
-<p><a href="../../goldenPath/help/customTrack.html#optParams" target ="_blank">URL optional 
-parameters</a> section of the Custom Tracks User's Guide.</p>
+For example, you can use the following command to hide every track and set the knownGene track to 
+the pack visibiblity:</p>
+<p><code><a href=../cgi-bin/hgTracks?db=hg38&hideTracks=1&knownGene=pack>http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&hideTracks=1&knownGene=pack</a></code></p>
+
+<p>Composite tracks have additional URL parameters that encode options to hide, select, and 
+display subtracks.</p>
+<ul>
+<li><em>trackName</em>_hideKids=1</li>
+<li><em>trackName</em>_sel=1</li>
+<li>ignoreCookie=1</li>
+</ul>
+<p>For example, the following URL hides all tracks (&amp;hideTracks=1), hides a specific composite
+track's default subtracks (&amp;refSeqComposite_hideKids=1), turns on one specific subtrack 
+(&amp;ncbiRefSeqCurated=full), and checks a box to display that subtrack 
+(&amp;ncbiRefSeqCurated_sel=1).
 
+<pre><a href="https://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&hideTracks=1&refSeqComposite_hideKids=1&ncbiRefSeqCurated=full&ncbiRefSeqCurated_sel=1">https://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&hideTracks=1&refSeqComposite_hideKids=1&ncbiRefSeqCurated=full&ncbiRefSeqCurated_sel=1</a></pre>
 
 <a name="link3"></a>
 <h2>Linking to the Browser to get gene information</h2>
 <p>
 To jump directly to a gene's position on the Genome Browser, set the position parameter in the 
-URL to a gene symbol (TP53, MTOR, KRAS, etc.) and add the       
-parameter <code>singleSearch=knownCanonical</code>. For example, this link will open the
-Genome Browser for the  hg19 human assembly at the position of the knownCanonical transcript
-associated with TP53:</p>
-<pre><code><a href="../cgi-bin/hgTracks?db=hg19&singleSearch=knownCanonical&position=TP53" target="_blank">http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg19&singleSearch=knownCanonical&position=TP53</a></code></pre>
+URL to a gene symbol (e.g., TP53, MTOR, KRAS) and add the parameter 
+<code>&amp;singleSearch=knownCanonical</code>. For example, the following link will open the
+Genome Browser for the hg19 human assembly at the position of TP53 on the knownCanonical dataset
+</p>
+<p><code><a href="../cgi-bin/hgTracks?db=hg19&singleSearch=knownCanonical&position=TP53" target="_blank">http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg19&singleSearch=knownCanonical&position=TP53</a></code></p>
 <p>
 <a name="gene"></a>
-You can also link directly to gene description pages from the URL. The following URL     
-connecting to 'hgGene' will open up the Genome Browser description page
-containing funtion information, expression profile, and links to associated information for the above gene.
-Note the use of the URL parameter <code>hgg_gene=</code>:</p>
-<pre><code><a href="../cgi-bin/hgGene?db=hg19&hgg_gene=TP53" target="_blank">http://genome.ucsc.edu/cgi-bin/hgGene?db=hg19&hgg_gene=TP53</a> </code></pre>
+You can also link directly to gene description pages from the URL. Instead of a position search,
+gene descriptions use the <code>&amp;hgg_gene=</code> URL parameter. The following URL connecting
+to 'hgGene' will open up the Genome Browser description page containing protein function, 
+expression profile, and links to additional information for the gene TP53.
+</p>
+<p><code><a href="../cgi-bin/hgGene?db=hg19&hgg_gene=TP53" target="_blank">http://genome.ucsc.edu/cgi-bin/hgGene?db=hg19&hgg_gene=TP53</a> </code></p>
 
 
 <h2>Loading data using a URL</h2>
 <a name="ctUrl"></a>
 <h3>Load Custom Track data with a URL</h3>
 <p>
-You can combine the URL visibility settings with the <code>hgct_customText=</code> parameter using
+You can combine the URL visibility settings with the <code>&amp;hgct_customText=</code> parameter using
 a track line you would otherwise put in the <a href=../cgi-bin/hgCustom>custom track 
-input box</a>. The following is an example of the hgct_customText URL variable:</p>
+input box</a>. The following is an example of the <code>hgct_customText</code> URL variable, where
+"%20" is the URL encoding for spaces:</p>
 <p>
-Try the following example of the hgct_customText URL variable, note that the hub only has data 
-on chromosome 21:
-<pre><a href=../cgi-bin/hgTracks?db=hg38&hgct_customText=track%20type=bigBed%20bigDataUrl=https://genome.ucsc.edu/goldenPath/help/examples/bigBedExample.bb>http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&hgct_customText=track%20type=bigBed%20bigDataUrl=https://genome.ucsc.edu/goldenPath/help/examples/bigBedExample.bb</a></pre>
+Try the following example of the hgct_customText URL variable.
+<pre><a href=../cgi-bin/hgTracks?db=hg38&hgct_customText=browser%20position=chr1%20track%20type=bigBed%20bigDataUrl=https://genome.ucsc.edu/goldenPath/help/examples/bigBedExample.bb>http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&hgct_customText=track%20type=bigBed%20bigDataUrl=https://genome.ucsc.edu/goldenPath/help/examples/bigBedExample.bb</a></pre>
 </p>
 
 <a name="hubUrl"></a>
 <h3>Load a Track Hub with a URL</h3>
-<p>Similar to Custom Tracks, track hubs can be loaded into the URL usig the <code>hubUrl=</code>
-parameter. This parameter takes input similar to the <a href=../cgi-bin/hgHubConnect#unlistedHubs>Track Hub interface</a>. Try the
-following example for reference:</p>  
-<pre><a href=../cgi-bin/hgTracks?hubUrl=https://genome.ucsc.edu/goldenPath/help/examples/hubDirectory/hub.txt&genome=hg19>http://genome.ucsc.edu/cgi-bin/hgTracks?hubUrl=https://genome.ucsc.edu/goldenPath/help/examples/hubDirectory/hub.txt&genome=hg19</a></pre>
-
+<p>Similar to custom tracks, track hubs can be loaded into the URL using the 
+<code>&amp;hubUrl=</code> parameter. This parameter takes input similar to the
+<a href=../cgi-bin/hgHubConnect#unlistedHubs>track hub interface</a>. Try the following example
+for reference:</p>  
+<pre><a href=../cgi-bin/hgTracks?hubUrl=https://genome.ucsc.edu/goldenPath/help/examples/hubDirectory/hub.txt&db=hg19>http://genome.ucsc.edu/cgi-bin/hgTracks?hubUrl=https://genome.ucsc.edu/goldenPath/help/examples/hubDirectory/hub.txt&db=hg19</a></pre>
+
+<p>Hubs track visibility can also be changed from the URL parameters. The following link loads a
+specific track from a supertrack with multiple composite subtracks.</p>
+<pre><a href"https://genome.ucsc.edu/cgi-bin/hgTracks?db=hg19&hubUrl=http://hgdownload.soe.ucsc.edu/hubs/gtex/hub.txt&hideTracks=1&gtexRnaSignalMaleYoung_hideKids=1&gtexRnaSignalMaleYoung=full&gtexRnaSignalSRR1311243=full&ignoreCookie=1">https://genome.ucsc.edu/cgi-bin/hgTracks?db=hg19&hubUrl=http://hgdownload.soe.ucsc.edu/hubs/gtex/hub.txt&hideTracks=1&amp;gtexRnaSignalMaleYoung_hideKids=1&amp;gtexRnaSignalMaleYoung=full&amp;gtexRnaSignalSRR1311243=full&ignoreCookie=1</a></pre>
 
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