uniform rank insignia & other

[max payload]

Now, I've placed this topic elsewhere on these forums before... here's trying again:

What sort of background, if any, is there to the airline uniform rank insignia, in particular those of the ground staff?
I see a great variety of bars and colors on many a sleeve... red, white, green, blue... even red caps on loading staff.
Is there a standard per discipline? Catering, engineering, operations?
Did ICAO or IATA ever venture out to try and recommend a practice for rank and function insignia?

Similarly for airline department codes.
FH = Freight Handling, PH = Passenger Handling, easy ones.
Then the reasoning gets murkier with other, more exotic combinations.
Same question- did ICAO or IATA ever venture out to try and recommend a practice for department/office/function naming?

And indeed, I've got nothing better to do :}

:ok: Max

[max payload]

Well, I can answer my second question it seems:
Apparently called Office Function Designators Codes, one can supposedly find these in IATA's Airline Coding Directory... can someone please confirm? A bit pricey to just go ahead and purchase for a look-see.

:ok: Max