I know that many English-speaking Muslims, when writing Muhammad's name, will add PBUH (peace be upon him) afterward. I was just really intrigued by this because not only does this seem very standardized among English speaking Muslims (not in the sense of everyone doing it- I have no idea- but in the sense that everyone uses that acronym), it is actually an English acronym, not an Arabic one. In Judaism, there are some acronyms that are used- in fact, we have one for "peace be upon him," AH for alav hashalom/aleha hashalom (which we use for people who have passed away)- but they're generally Hebrew phrases that have been used for centuries. I've never heard of an acronym being so popularly used based off an English phrase that's a translation of an original phrase.
So where did PBUH come from? How did it become the standard? Do other languages have an equivalent acronym?
EDITED: Just to make my question clearer- how did this English-LANGUAGE (not English-LETTER) acronym become standardized among English-speaking Muslims, as opposed to what would seem to me (though possibly more just due to my own cultural background and subsequent biases) would be the more simple and universalized thing of an Arabic-LANGUAGE (in English transliteration) acronym? When/why did people start writing it in English and not Arabic?
Just commenting on a part of your question(specifically the AH acronym used in Judaism), not providing a proper answer, if allowed here:
Arabic for PBUH is 'Alaih Salam' and this particular phrase is traditionally used by muslims after the names of peophets, for example Isa Alaih Salam(AS for short) is how a muslim woud refer to Jesus Peace Be Upon Him.
It's a little different with Prophet Muhammad(PBUH), however, as the prayer any muslim is supposed to say after hearing him being mentioned is 'Salallahu Alaihi wa (Aalihi wa) Salam', roughly meaning 'May Allah's Praise be Upon Him and (His Family and) Peace'. The par in brackets is optional and sometimes skipped. That's why SAW or SAAW is sometimes used instead of PBUH.(a good read on this: https://contemplatequran.wordpress.com/2015/06/05/seerah-series-part-2the-meaning-of-sallallahu-alaihi-wasallam/)
Similarly 'Radiallah Anhu' meaning 'May Allah be Pleased with Them' is affixed after the names of the Prophet's companions and 'Rehmatullah Alaih' meaning 'May Allah have Mercy on Them' after the names of saints, scholars and other venerated and pious people. Both abbreviated as RA.
In my understanding, PBUH is used nistead of SAW for the same reasons muslims sometimes say God instead of Allah: it might feel more natural to use words commonly used in the language you are speaking at the moment instead of foreign ones.