Listing Prefixes
If listing prefixes are enabled for your MLS, you can click List Prefixes under Main Listings on the Admin menu to create or modify them. A listing prefix is a two-character label used in listing numbers. The prefix is commonly set for the year the listing is entered.

Click the buttons at the bottom of the page to add or remove a prefix. Adding or removing a prefix does not change existing listings that use the prefix. Only new listings will be affected. If your MLS uses a prefix to signify the year that a listing was entered, we recommend removing the prior year's prefix at the start of the new year to prevent users from selecting an incorrect prefix.
Listing prefixes are available if the MLS setting Use listing prefixes is set to On.