Re: (m/f) in job ads
Certainly in Germany, this is because discrimination is outlawed, but the grammar is such that job titles are different for men and women. A male programmer is "ein Programmierer", a female programmer is "eine Programmiererin" (you can occasionally still see that in English: "an actor" vs "an actress"). This applies to *all* job titles. That means you can either advertise for "ein(e) Programmierer/Programmiererin" or "ein Programmierer (m/w)" - and most choose the latter.
I expect the same applies to most European languages.