Sounds like a worse version of non-standard (X-*) HTTP headers: https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers#non-standard_headers https:/

Sounds like a worse version of non-standard (X-*) HTTP headers: https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers#non-standard_headers https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/... Happens a lot when standard is not specific enough.