I am building a theme where some of my assets are combined and minified already. These files are named by the SHA1 of the contents (an idea borrowed from GWT). If these file's contents change (i.e. I release a new version of the theme) the names of these files will change.

Because of this these files may be safely cached forever by the client.

Is there any way to alter the cache headers for these assets to specify that they may be cached forever?