These are known as keywords, and they are a special property you can set on your source files. They operate mostly the same, but you have to set the property on each file before the text replacement is done.
Check out the docs at:
so it works
Shame on me.
It's in the Docs and not hard to find :-)
But I've looked over it.
Sometimes you need to ask a forum to find out :-/
svn propset svn:keywords "Id" some.file
In phpBB we trust. :roll: