Possibly the abbreviation of a romance language (French, Spanish, Italian, Portguese etc.) spelling of "for example" ("par exemple", "por ejemplo", "per esempio", "por exemplo"...)
OP here: You've got it. Spaniard, "por ejemplo"
That makes way more sense than english's weird use of the latin e.g. for exempli gratia. And now I learn the actual romance languages don't even use it.