The plug-in ID element is a string used to identify a particular plug-in interface function. Multiple plug-in interfaces can be grouped with the same Plug-in ID for a similar function. Plug-in ID values are predefined by SALT. Arbitrary string values are not permitted.

SALT supports the P_CUSTOM_TYPE and P_CREDENMAP plug-in ID, which is used to define plug-in interfaces for custom typed buffer data handling, and map Oracle Tuxedo user ID and group ID into username/password that HTTP Basic Authentication needs.