[mod.telecom] part of 403 is "temp."?

cmoore@BRL.ARPA.UUCP (12/05/86)

Yesterday, I looked at list of area codes in the Orange County (California)
directory, and noticed that 403 was listed as the area code for Alberta,
Yukon Territory and Northwest Territories with the latter 2 noted as "TEMP."!
Why TEMP?