Keywords can be placed within text-files and get expanded during checkout by SVN.
Example: $Id$.
For SVN, this must be enabled on a per file basis.
Provide an Automation to do this.
Configuring SVN Client to auto-add svn properties:
http://wiki.apache.org/jakarta-commons/UsingSVN
Example command-line which adds svn:keywords on existent files:
svn propset svn:keywords "Id HeadURL Date Author Rev" -R trac property 'svn:keywords' set (recursively) on 'trac'