[Mathias]

WepProf.? exists for any exotic weapon proficiencies, specific martial weapon proficiencies, or a class that grants a specified list of weapons.

#hasfeat[fWepSimple]
#hasfeat[fWepMart]

are the other items you're after.

Complain to Rob and Colen that WepSpec.? (along with WepGrFoc.? and WepGrSpec.?) don't exist, although by looking at the script for Weapon Focus, I can see how to make a version of those feats that does add the appropriate tag.

The way to find this is to add something that grants the proficiency you want (and I suggest you try getting at it multiple ways, for example Light Crossbow proficiency comes with fWepSimple, but a Wizard gains WepProf.wCrsLight), then View menu, Floating Info Windows, Show Hero Tags - keep that list up, and watch what's added as you add classes and feats.

Here's an example PreReq from Pathfinder 8 - the class in question requires proficiency in any type of crossbow:

if (hero.tagis[WepProf.wCrsHand] + hero.tagis[WepProf.wCrsHeavy] + hero.tagis[WepProf.wCrsLight] + hero.tagis[WepProf.wCrsRpHvy] + hero.tagis[WepProf.wCrsRpLgt] + #hasfeat[fWepSimple] <> 0) then
@valid = 1
endif

or, to find an exotic weapon proficiency:

if (tagis[WepProf.wPFSawtoot] <> 0) then