What is the SLID and where can I find it?
The Special List ID, or SLID, is an encoded identification to allow the platform to recognize a List in sign up forms and opt-out links. Specifically, the SLID is used in forms generated through the Subscription Form Wizard as well as Forward To A Friend forms. SLIDs are generally a hidden identification
To find the SLID of a list, view the LIst Matrix.