Evan: For the purpose of teaching, I learned and taught it as "PEMA". But, when I went to school and studied order of operations, a long time ago, we were taught in English sentences.
I don't even know that those two abbreviations mean!
Abbreviations sometimes are more confusing - more stuff to remember and formula-istic (if there is such a word).
If the work is documented with good, English phrases and sentences, I believe it conveys more accessible meaning and speaks more to understanding of what is being presented than abbreviations.