Line format:
wiki code (subproject.project)
article title
monthly total (with interpolation when data is missing)
hourly counts
In the wiki code field, the subproject is the language code (fr, el, ja, etc) or meta, commons etc.
The project is one of b (wikibooks), k (wiktionary), n (wikinews), o (wikivoyage), q (wikiquote), s (wikisource), v (wikiversity), z (wikipedia).
However, I've been coming across a large number of wiki codes "en.m". The "m" code is undocumented. It appears to be the mobile version of Wikipedia, but can anyone confirm that? Should the page be updated with this information?