As mentioned in post 125 upthread, the Office of Personnel Management defines all regular federal jobs with a classification number. The OPM HANDBOOK OF OCCUPATIONAL GROUPS AND FAMILIES lists them.

TSA screeners appear to be based on 1802, Compliance Inspection and Support Series. Federal police are 0083 series. Security guards are 0085. CBP are 1895.

Of course, I do not know how much leeway TSA has to “exempt” itself from these rules, Out of an Abundance of Caution Anything for Security Gotta Prevent Another 9/11™ doncha know.