I completely agree with the above comments - from a dispatchers prospective earlier on it was getting very confusing just having each code thrown around, before even adding the fact they meant different things to different people!
So what i think the best option would be is to have a standard set of say 10 to 15 of the most common 10 codes for the generic, most common messages (e.g. On duty, in service, rest break, backup, out of service, copied etc) then everything else to be in understandable-to-everyone English really which i do not see to much of a trouble in - remember any option can always be trialed etc.