I do not believe there is a mechanism for the z/OSMF Jobs REST API to restrict which jobs can be submitted and/or which HTTP headers are used on the submit. I'm scratching my head though, why do you want to restrict use of this particular header? And is it really the use of the header that you want to restrict, or something else? Do you have a similar issue/desire to restrict when using the TSO SUBMIT command? A little context might help us identify a possible solution.