Years, Letters and Numbers to the right of the colon.
If the call number is the same up until the colon and then varies, the correct order after the colon is Years, Letters, then Numbers. For example, the following documents are arranged in the correct order:
EP 1.23: 998 ("998" represents the year 1998; after 2000 years include the full four digits.)
EP 1.23: A-62 (The letter "A" comes after the year 1998.)
EP 1.23: 91-44 ("91" is a number so it is filed last.)
D 1.2:
D 1.13:
D 1.33:
D 1.105: