Certain contractions can have a different meaning given the context. The combo dots 2,5, as an example, can mean double "c" or "con" dependent upon how it is placed. The combo "3,4,5" ccan be used to indicate "ar" as in "carry" or be a part of a number's square root. The combo "2,6" can be the word "enough" or the contraction for "en" if attached to a word. Back translators do quite well; just not 100% -- and I think that is the point.