This regular expression will find Canada Postal Code in a string.
[A-Za-z]\d[A-Za-z][ -]?\d[A-Za-z]\d
Canada uses ANA NAN format.
From Wiki:
The system was gradually introduced starting in April 1971 in Ottawa.
The letters D, F, I, O, Q, and U are not used to avoid confusion with other letters or numbers.
From Goverment of Canada:
The postal code is a six-character code defined and maintained by Canada Post Corporation (CPC) for the purpose of sorting and delivering mail.
The characters are arranged in the form 'ANA NAN', where 'A' represents an alphabetic character and 'N' represents a numeric character ( e.g. , K1A 0T6).