Since I have never seen this anywhere else, I thought I would post ALL the valid PK commandline options. The most interesting is probably the optional hardware class option (+hwclass). The rest are fairly well known.
PK COMMAND LINE OPTIONS:
+playrecording [demo name]
+name [player name]
+map [map name]
+hwclass [tnl, nv20, nv25, r200, nv30, nv40]