I use them on occasion. Therapists custom profession settings makes it nice and easy to set up such a system.
With me it's not so much "caste" as "proffesion".
I start out with only a handful of proffesions and slowly grow to this full list (fullish, there are a few I'm sure I'm forgetting):
Leaders:
Führer: Leader - Manager/Organizer/Record Keeper/Broker
Veranstalter: Organizer - Manager
Buchhalter: Book Keeper/Broker
Labors:
Arbeiter (Worker): Haulers
Bergmann: Miner
Betreiber: Operator (Pumps), Levers
Jäger (Hunter): Ambusher, Herbalist, Fisher, Trapper, Woodcutter
Craftsmen:
Maurer: Mason, Mechanic (Stone)
Tischler (Cabinetmaker): Carpenter, Bowyer
Juwelier (Jeweler): Gem Cutter/Setter
Handwerker: Craftsman - Bone/Wood/Stone/Wax, Strand Extractor
Graveur: Engraver
Lederer: LeatherWorker
Weber: Weaver, Spinner
Näherin (Seamstress): Clothemaking
Töpfer: Potter (Furnace Operator), Glazer
Glasmacher: Glassmaker
Farming:
Landwirt (Farmer): Grower, Herbalist, Shearer
Müller: Miller, Thresher, Press Operator
Imker: Beekeeper
Käser: Cheese maker, Milker
Metzger: Butcher, Fish Cleaner, Animal Hauler
Koch: Cook, Fish Cleaner
Brauer: Brewer
Köhler (Charburner): Furnace Operator, Woodburner
Seifensieder: Soap Maker, Lye Maker, Potasher
Färber: Dyer, Tanner
Smiths:
Schmied (Smith): Metal/Armor/Weapon Smith, Mechanic (Metal)
Schmelzer: Smelter
Mechaniker: Mechanic (Stone and Metal), Seige Engineer
Medical:
Chefpathologe: Chief Medical Examiner, Diagnostician
Chirurg (Surgeon): Doctor
Amme: Nurse
Military:
Schütze: Marksman
Soldat: Soldier
Axtzwerg: Axdwarf
Speerzwerg: Speardwarf
Schwertzwerg: Sworddwarf
Hammerzwerg: Hammerdwarf