svn propset svn:keywords "Id" * will set the Id property to expand in your source code on everything. Coupled with a little
find action and you’ve got a whomper of a property setting command.
Subversion has the ability to substitute keywords%u2014pieces of useful, dynamic information about a versioned file%u2014into the contents of the file itself. Keywords generally describe information about the last time the file was known to be modified. Because this information changes each time the file changes, and more importantly, just after the file changes, it is a hassle for any process except the version control system to keep the data completely up-to-date. Left to human authors, the information would inevitably grow stale.
For example, say you have a document in which you would like to display the last date on which it was modified. You could burden every author of that document to, just before committing their changes, also tweak the part of the document that describes when it was last changed. But sooner or later, someone would forget to do that. Instead simply ask Subversion to perform keyword substitution on the LastChangedDate keyword. You control where the keyword is inserted into your document by placing a keyword anchor at the desired location in the file. This anchor is just a string of text formatted as $KeywordName$.
All keywords are case-sensitive where they appear as anchors in files: you must use the correct capitalization in order for the keyword to be expanded. You should consider the value of the svn:keywords property to be case-sensitive too%u2014certain keyword names will be recognized regardless of case, but this behaviour is deprecated.
Subversion defines the list of keywords available for substitution. That list contains the following five keywords, some of which have aliases that you can also use: