I’ve just noticed in the pugs::hack document a useful tip for informing subversion about the charset of a file.
svn propset svn:mime-type "text/plain; charset=UTF-8" myfile
A quick browse through the subversion list archives shows that it appears to be “not forbidden” even if not 100% officially sanctioned. It’ll certainly work for its intended purpose of displaying character sets correctly when browsing a repository via HTTP.
Jabbering Giraffe 