Unless they are like Burnaby which uses a disposition code to tell dispatch the conclusion of a call, ie : Fire extinguished, MVA, Public assist etc, than I am going to say the Enterphone code of an apartment. I could be wrong , I have never heard Abby or Mission or Chilliw, use disposistion codes, I will listen today to all three depts and try to see if this is something new. EHS always asks for code to get in front door of apartments, and because they download certain types of calls that FD can handle (which is many time closer), thats my edumucated guess.
Surrey Fire Department (which sadly can no longer be monitored) uses Code 58 for a drug overdose and Code 59 for someone Deceased. Would have to agree with BC_Scan on this one as I too haven't heard any of the UFV fire departments utilizing disposition codes.
Only one time in 35 years have I heard ANY alarm or door codes over the air. The Chief will ask to call me "on the cell phone OR come to the car for a face to face. As well, I NEVER hear any names of ANY civilian victim or RP given over any clear channel! That one time got the firefighter in SERIOUS Dutch. I know. He is a friend of mine.