1 n. — Administration
a structured six-character alphanumeric code specifying a Canadian mailing address in a machine-readable format (see Image 1).
Type: 1. Origin — In the UK, the equivalent term is post code, while in the US it is zip code. Postal code appears to have originated in Canada and the term is most prevalent in Canada (see Chart 1). Postal codes are used in the mechanized sorting of letters and were first implemented in the early 1970s. The first letter of the code starts with A in the east (Newfoundland and Labrador) and moves west in alphabetical order to V (British Columbia) and ends in the north with X for Nunavut and the Northwest Territories and Y for the Yukon. Image 1 shows the geographical delimitation that is expressed in the first part (the first three letters and numbers) of the postal code for Metro Vancouver (see Metro (3)). For instance, a postal code of V5V 5C5 specifies an address in the middle of the map, in East Vancouver, marked by the orange square. The last part of the code refers to the side of the street and other details (note the difference from early postal code orthographic conventions; see the 1978 quotation).
See also COD-2, s.v. "postal code", and Gage-3, s.v. "postal code", which are marked "Cdn", and ITP Nelson, s.v. "postal code", which is marked "Canadian".
See also: Metro (meaning 3)
- The UK post code was implemented between 1959 and 1974. The Canadian code resembles the UK code, in that it uses an alphanumeric system unlike the US zip code which is all numbers. The concept may derive from the UK, but the linguistic form is uniquely Canadian.
- 1967  For two years a file has been growing in the headquarters of the Post Office Department on the possible adoption of a postal code for Canada. The choices range from a five-numeral U.S.-type ZIP (Zone Improvement Plan) Code to a combination of letters, numbers and symbols. A committee that has been studying the problem is still a long way from announcing its conclusion, but more than the choice of a specific code is involved, for during the next 20 years the volume of mail in Canada will double. 
- 1969  In its 100-page report, it recommended: – Establishment of a new task force to determine in detail the nature of the automation and mechanization the Post Office should adopt, which might include design of a postal code [...]. 
- 1978  A friend of ours, talking to a representative of the federal Government on the phone the other day, was asked for his postal code, which is M5S-1M5. 
- 1980  An indicator of improvement is the increase in public acceptance of the postal code. Code use has increased to 80 per cent from 56 per cent in three years. Among large volume users, code use is 90 per cent. 
- 1989  AS I SETTLE INTO the lower levels of old age I find that my memory often functions quite erratically. Without straining I can remember our home phone number from my boyhood but at times I have difficulty in coming up immediately with my present number. Most of the time, though, I remember my postal code. 
- 1999  In the U.S., where about 15 states have brought in electricity competition, there are already numerous Internet based companies taking advantage of deregulation.
One Web site, www.utility.com, acts as an on-line discount electricity retailer. Customers type in their zip codes (Canadian postal codes are not accepted), and the site searches for the company's local prices. 
- 2009  Most of the volunteers at the event do their work in the basement of TCU Place. Mailroom volunteers sort pledge forms by postal code, while those in the treasury count stacks of money and process credit information to a soundtrack of rustling bills and the clicks and hums of adding machines. Extra rooms are set up to take the calls the operators on stage can't handle, and in the main room volunteers on break play cards and line up to eat donated pizza and ice cream. 
- 2016  This app harnesses technology and takes flyer and coupon scanning to the extreme. Enter your postal code and you'll find flyers from just about every local retailer, plus coupons for top brands in groceries, baby supplies, health and beauty, and more. 
2 n. — originally in figurative use
the area designated by a postal code.
Type: 1. Origin — In recent years, postal code has become identical with the area serviced by a particular postal code (via a process that is called metonymical change). In the mid 1980s, the use of "postal-code areas" can still be seen (see the second 1986 quotation), while in later quotations this is condensed to just postal code as in "Canada's poorest postal code" in the 1999 quotation, which refers to the Downtown Eastside community of Vancouver, which has its own postal code that is used metonymically for that neighbourhood (see also the later quotations).
- 1986  Alas, the generation gap. Pro wrestling for me was Sweet Daddy Siki, The Sheik, Pampero Firpo - The Wild Bull Of The Pampas, Waldo Voln Erich, Johnny Powers and Dewey Robertson. Robertson was from Keswick, Ont. I knew that much. But this was a whole different bag. I could feel that when we took our seats, which I believe were a postal code away from the ring. 
- 1986  "All we do is provide rankings of postal-code areas which offer the highest potential for a particular product or service that a client is looking to target.
The client will take this information to a list broker who will rent out the names and addresses of that target group." 
- 1999  Still, this week, posters are going up throughout Canada's poorest postal code: "MOOSE! ELK! DEER! A FREE NEW YEAR'S EVE BARBECUE." Noon - 4 p.m, Friday, Dec. 31, cooked under the awning of the abandoned Woodwards department store in the 300-block of Abbott Street. 
- 2013  For the first time this year, the report also factored in differences in socioeconomic status and found differences in certain hospitalization rates - specifically attempted suicides and self-harm - based on whether patients lived in a more affluent or less affluent postal code. The report revealed that suicide and self-harm rates are considerably higher in Canada's rural and northern areas. 
- 2015  The latest is in West Vancouver, where old arguments have, in a sense, been turned on their head. In Canada's richest postal code, it's not residents upset about the garish nature and outlandish size of the houses going up - the monster-house squabble has often been fuelled by jealousy and racism - it's the fact the municipality is trying to restrict how big the structures can be. 
Images:
Image 1: Postal codes in Metro Vancouver. Source: http://www.lahistoriaconmapas.com
Chart 1: Internet Domain Search, 6 Jun. 2013