Added speal about shlib version numbers.

Implicitly requested via -ports email by:	Satoshi

handbook/policies.sgml

@@ -1,4 +1,4 @@
-<!-- $Id: policies.sgml,v 1.5 1996-11-05 09:41:38 max Exp $ -->
+<!-- $Id: policies.sgml,v 1.6 1996-12-09 11:18:52 obrien Exp $ -->
 <!-- The FreeBSD Documentation Project -->
 
 <chapt><heading>Source Tree Guidelines and Policies
@@ -137,3 +137,30 @@ should be added and it should states things like:
  <item> Where to send patches back to the original authors
  <item> Perhaps an overview of the FreeBSD-specific changes that have been made.
 </itemize>
+
+<sect><heading>Shared libraries
+<label id="policies:shlib">
+</heading>
+
+<p><em>Contributed by &a.asami; and &a.obrien;.
+  <newline>9 December 1996.</em></p>
+
+  <p>If you are adding shlib support to a port or other piece of software that
+    doesn't have one, the version numbers should follow the following rules,
+    which in general have nothing to do with the release version of the
+    software.
+  <p>The three principles of shared library building (tm) are:
+
+  <itemize>
+    <item>Start from 1.0
+    <item>If there is a backwards-compatible change, bump minor number
+    <item>If there is an incompatible change, bump major number
+  </itemize>
+
+  <p>For instance, added functions and bugfixes are (2).  Deleted functions,
+    changed function call syntax type changes fall in (3).
+
+  <p>Stick to version numbers of the form major.minor (x.y).  Our dynamic
+    linker does not handle version numbers of the form x.y.z well.  Any
+    version number after the ``y'' is ignored, and cannot be used to 
+    differentiate between two different shared library versions.