<p>The MS source server technology uses an initialization file named srcsrv.ini. One of the values identifies the source server location(s), e.g.,</p>

<pre><code>MYSERVER=\\machine\foobar
</code></pre>

<p>The docs leave much unanswered about this value. To start with, I haven't been able to find the significance of the value name, i.e., what's on the left side--and I don't see it used anywhere else. Hewardt &amp; Pravat in <a href="http://www.advancedwindowsdebugging.com/" rel="nofollow noreferrer">Advanced Windows Debugging</a> say "The left side ... represents the project name", but that doesn't seem to jibe with MS's "MYSERVER" example.</p>

<p>What <i>is</i> the significance of the left side? Where else is it used? Does the value reference a server or a project, and is there one per server, or one per project?</p>

For anyone looking into this in the future, I received the following information from MS:
The name on the left side is the logical name of a version 
  control server. The name is also used in the source-indexed symbol files 
  (pdb). For example, a symbol file may contain this string value:
MYSERVER=mymachine1.sys-mygroup.corp.microsoft.com:2003
and the source files are referenced like this in pdb:
*MYSERVER*/base/myfolder/mycode.c
When SrcSrv starts, it looks at Srcsrv.ini for values; these values override the information contained in the .pdb file:
"MYSERVER=mymachine.sys-mygroup.corp.microsoft.com:1666" overrides
"MYSERVER=mymachine1.sys-mygroup.corp.microsoft.com:2003"
This enables users to configure a debugger to use an alternative source control server at debug time. The info is documented at
http://msdn.microsoft.com/en-us/library/ms680641.aspx
.
So, it is a logical name for a source server, and its value can be changed at debug time to reference a different server than the one originally used when the PDBs were created.