Selector name
The text string name of the selector. This is not required for anything other than readability but when there get to be more than a couple selectors it’s nice to give them names like “Begin/end trans: STATUS messages” and “Database server errors”.
Message types
There is a check box for each predefined message type as well as for each single-bit user type. (Free form user types will be fully supported in subsequent versions.) Leaving all message types checked means the message type field is not evaluated.
OS (Operating System) identifiers
An edit box is supplied for entering the process ID and/or thread ID in hex format.