Timothy Barton May 6, 2015:

Native language Your profile says English is your native language. Even if we allow for typing mistakes in your question, the fact you say " Could you pls guess wht could this be?" [sic] and not "what this could be" (a typical mistake among non-native speakers) demonstrates that your native language is not English. Please correct the false information on your profile. I recommend that you stick to translating into your native language or you'll have some very unhappy clients.

BrigitteHilgner Jan 20, 2006:

Sorry - I have difficulties understanding your English, therefore I really have to guess.
P.M. might be "per month" (pro Monat), but this is a wild guess.
You might want to try:
www.abkuerzungen.de