This filter is a greatly simplified multi-language filter. It uses very simple non-HTML tags to mark multi-language blocks. Namely {mlang XX} {mlang} pairs, where XX is the Moodle short name for the language pack (i.e., en, fr, eu, es, es_mx, etc.) It uses the same tags as the filter_multilangsecond plugin (to be compatible with it), but there is one difference between the two. This filter allows standalone {mlang} tags that don't require adjoining alternative language tags. This makes the filter more flexible at the cost of potentially producing empty sets of tags.