Hyper-Schema security section needs to be brought up to best practice levels

[handrews]

This issue tracks bringing it up to something resembling compliance with RFC 3552: Guidelines for Writing RFC Text on Security Considerations

[awwright]

Other hypermedia documents (like HTML, HAL, CoAP's CORE) could give some pointers and direction, perhaps.

[handrews]

I submitted PR json-schema-org/json-schema-spec#487 to make some progress on this for draft-07, but fully doing this can wait until a future draft.