[hellbender]

I really don't know much about Walther firearms, but here's what Wikipedia says about "PPK":

Walther PPK. Its German acronymous name stands for Polizeipistole Kriminalmodell (Police Pistol Detective Model - implying it was more concealable than the original PP model and hence better suited to plainclothes or undercover work)

[patton]

Actually, that is Police Pistol Criminal Model.