Constant HTTP_OTHER_METHOD 

pub const HTTP_OTHER_METHOD: Capability;

Every other method http.request takes, gated as http.<method> with the method lowercased: http.request("TRACE", …) checks http.trace. Kept out of [CORE_CATALOG], whose consumers read a templated name as mcp.<server> and concretize it per declared server; see uncataloged_http_method.