post-revprop-change — Notification of a successful revision property change.
The post-revprop-change hook is run
          immediately after the modification of a revision property
          when performed outside the scope of a normal commit.  As you can
          derive from the description of its counterpart, the
          pre-revprop-change hook, this hook will
          not run at all unless
          the pre-revprop-change hook is
          implemented.  It is typically used to send email
          notification of the property change.
If the post-revprop-change hook returns a
          nonzero exit status, the change will
          not be aborted since it has already
          completed.  However, anything that the hook printed
          to stderr will be marshalled back to the
          client, making it easier to diagnose hook failures.
The command-line arguments passed to the hook program, in order, are:
Repository path
Revision whose property was modified
Authenticated username of the person making the change
Name of the property changed
Change description: A (added),
              D (deleted), or M
              (modified)
Additionally, Subversion passes to the hook program, via standard input, the previous value of the property.