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<P>

<H1><A NAME="SECTION00010000000000000000">
Controlling Linking Summary</A>
</H1>
This is a PM article that was written by mathwizard, and also applies to PlanetPhysics linking of entries. You can see the complete entry at:
<!-- MATH
 $http://planetphysics.org/op=getobj\&from=collab\&id=18$
 -->
<SPAN CLASS="MATH"><IMG
 WIDTH="529" HEIGHT="37" ALIGN="MIDDLE" BORDER="0"
 SRC="img1.png"
 ALT="$http://planetphysics.org/op=getobj\&amp;from=collab\&amp;id=18$"></SPAN>

<P>

<H2><A NAME="SECTION00011000000000000000">
Introduction</A>
</H2>

<P>
Noosphere's automatic linking <A NAME="tex2html1"
  HREF="../../00/SimilarityAndAnalogousSystemsDynamicAdjointnessAndTopologicalEquivalence/SimilarityAndAnalogousSystemsDynamicAdjointnessAndTopologicalEquivalence.html">system</A>
handles most inter-entry linking instances properly. However, a small fraction of the time, it does not have enough information based on <A NAME="tex2html2"
  HREF="../../00/Definition2/Definition2.html">concept</A>
label metadata (titles, synonyms, defines) and <A NAME="tex2html3"
  HREF="../../00/CategoryTheory/CategoryTheory.html">classification</A>
metadata to resolve ambiguous links. In these cases, something extra must be done to correct linking.

<P>
There are two families of methods to accomplish this. The first involves improving the metadata, beyond concept labels and classification. We introduce <SPAN  CLASS="textit">linking policy</SPAN> metadata to accomplish this.

<P>
The second family of methods involves pseudo-<SPAN CLASS="logo,LaTeX">L<SUP><SMALL>A</SMALL></SUP>T<SMALL>E</SMALL>X</SPAN> commands to steer the linking. We call this the <SPAN  CLASS="textit">in-situ</SPAN> method.

<P>
In-situ controls should be considered a last resort, as it is much more elegant and labor-effective to separate link controls from the text. For example, consider a situation where someone points out a problem with a link in your entry, entry <SPAN CLASS="MATH"><IMG
 WIDTH="19" HEIGHT="16" ALIGN="BOTTOM" BORDER="0"
 SRC="img2.png"
 ALT="$A$"></SPAN>. The errant link is due to a term defined in entry <SPAN CLASS="MATH"><IMG
 WIDTH="20" HEIGHT="16" ALIGN="BOTTOM" BORDER="0"
 SRC="img3.png"
 ALT="$B$"></SPAN>. This problem could be fixed if the author of <SPAN CLASS="MATH"><IMG
 WIDTH="20" HEIGHT="16" ALIGN="BOTTOM" BORDER="0"
 SRC="img4.png"
 ALT="$B$"></SPAN> improved its linking policy, or if you used an in-situ link steering command in <SPAN CLASS="MATH"><IMG
 WIDTH="19" HEIGHT="16" ALIGN="BOTTOM" BORDER="0"
 SRC="img5.png"
 ALT="$A$"></SPAN>. However, assume that the same linking problem is also present in 100 other entries, all of which link to <SPAN CLASS="MATH"><IMG
 WIDTH="20" HEIGHT="16" ALIGN="BOTTOM" BORDER="0"
 SRC="img6.png"
 ALT="$B$"></SPAN>. Rather than fixing the 100 entries with in-situ commands, it makes much more sense for the author of <SPAN CLASS="MATH"><IMG
 WIDTH="20" HEIGHT="16" ALIGN="BOTTOM" BORDER="0"
 SRC="img7.png"
 ALT="$B$"></SPAN> to modify its linking policy once, solving all 100 errant link instances.

<P>
The two families of methods are described below.

<P>

<H1><A NAME="SECTION00020000000000000000">
Linking Policy</A>
</H1>

<P>
The linking policy of an entry is a text field containing a set of directives, one per line. The currently-supported directives are described below.

<P>

<H2><A NAME="SECTION00021000000000000000">
Link Priority</A>
</H2>

<P>
This directive has the following syntax:

<P>
<PRE>
priority &lt;N&gt; [LABEL]
</PRE>

<P>
where <code>&lt;N&gt;</code> is a number and <code>[LABEL]</code> is an optional concept label defined by the entry. The default priority is 100, and integer values from 0 to 32767 are accepted. Smaller numbers mean higher priority. Examples are:

<P>
<PRE>
priority 10 normal
priority 200 "mapping \htmladdnormallink{function}{http://planetphysics.org/encyclopedia/Bijective.html}"
</PRE>

<P>
This directive is used as a tie-breaker when classification directives and category-based link steering fail to find a unique destination. Setting the priority higher than normal (closer to zero) results in an entry (or concept) being linked to &#8220;by default&#8221;. Setting it lower (above 100) would result in the entry or concept being linked to automatically only when the categorization of the other entry overlaps.

<P>

<H1><A NAME="SECTION00030000000000000000">
In-Situ Link Controls</A>
</H1>

<P>
The in-situ methods involve pseudo-<SPAN CLASS="logo,LaTeX">L<SUP><SMALL>A</SMALL></SUP>T<SMALL>E</SMALL>X</SPAN> commands you can put in your entry to steer linking. As mentioned before, they should be considered a last resort, with proper concept labels, classification, and linking policy as the first lines of defense.

<P>

<H2><A NAME="SECTION00031000000000000000">
Link Suppression</A>
</H2>

<P>
Sometimes it makes sense to block linking entirely for a portion of an entry, rather than simply steering a link to a different target.

<P>
<BR><HR>

Contributors to this entry (in most recent order):
<p>
<ul>
<li><a href="../../people.html#441">bci1</a></li>
</ul>
<p>
As of this snapshot date, this entry was owned by <a href="../../../people.html#"></a>.
<p>


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