Selling Partner APIs - x-amzn-RateLimit-Limit Response Header


The documentation speaks about the response header x-amzn-RateLimit-Limit being present for use:
selling-partner-api-docs/ at main · amzn/selling-partner-api-docs (
However, I have never seen this header actually show up in neither valid nor throttled responses.

Is this header implemented and, if so, when/where should we expect to see it?

System information:
C# Core 3.1 + RestSharp
Calling Orders/GetOrder (or any of the Orders APIs)
Example request/response info:
Date=Wed, 07 Apr 2021 19:09:44 GMT