RFCs (Requests for Comments) are documents relating to the technical development of the Internet, including specifications of protocols and other standards. Each RFC is assigned a sequential number upon publication.

As of September 2025, the latest RFCs have numbers in the 9800s, and there are only about 150 numbers left before 10000. When will the RFC series hit the 10000 mark?

This question resolves to the month of publication of the lowest-numbered RFC with a number greater than or equal to 10000. The list of published RFCs will be taken from the RFC Editor's website and the month of publication for a particular RFC will be determined by its header.

I will add more options and extend the closing time if needed as time goes on.

I may trade in this question as usual.