I just received this great question from one of our subscribers this week!
An address label on a catalog has many different pieces of information on it. Of course there is your Name and Address but also included are 3 or 4 other codes which mailers use to track your account and where they got your private information from.
1. Account or Customer Number
2. Source Code
3. Key Code
4. Offer Number
5. Certificate number
6. Reservation Number
Additionally there may be a mail preparation marking in the very first line on the address label called the Standard Mail Enhanced Carrier Route Flat. In this Subscribers case the ECRLOT stands for Enhanced Carrier Route Line Of Travel. This a discount Flat rate that bulk mailers receive for mailing 90 days in advance using the USPS. The codes are for internal use with the USPS.
There may also be other mail preparation markings such as:
Regular: Presorted Standard or PRSRT STD.
Nonprofit: Nonprofit Organization or NONPROFIT ORG. or NONPROFIT.
Basic, high-density, and saturation rate pieces will be marked ECRLOT, ECRWSH, or ECRWSS
As far as I know it is not important when removing your private information from direct mailers mailing lists.
Again, great question!