I'm not asking how to detect duplicate POST requests. I'm asking if we are supposed to. According to RFC 2616 (section 9.5), POST is used to submit some sort of record/resource/data to the server ...

Google Ads API v18 will stop working on August 20, and developers must upgrade to a newer version to avoid disruptions.

Reddit announced changes to its API a few months ago, but everyone is losing their minds about it now. What's going on?

POST requests make sense for packing tracking, you know, because of definition of postal. Okay bad joke but it is true, Google's package tracking API is now only accepting POST requests.