The filename extension usually gives you a broad idea of the contents, so I wouldn't go for it. In a remote future (1 month) you could be happy to remember that your template stuff was in those weirded-named files ending in
, and be able to separate it from the plain html. Moreover, I'd keep those files outside the directory tree exposed by the web browser, because someone could access those pages directly. So, these pages aren't strictly HTML (at least in their semantic) and aren't to be served by the webserver directly - why would you call them