To look for an entity with a specific pattern such as the a Canadian Postal Code the best path to take would be

Question $6$ options:

Look for each term with a length of $6$ that has numbers and letters,

Create a regex expression looking for letters followed by numbers followed by letter ect

Create a concept rule looking with terms with the first space being each letter in the alphabet

Create a predicate rule that looks for strings followed by letters with a distance of $1$ between them