Under U.S. federal law, men ages 18–25 must register with the Selective Service System to be eligible for most federal jobs. Federal agencies enforce this under hiring rules in 5 U.S.C. § 3328.

The wording is a bit strange - technically all men (18-25) must register. When I tried to register, I was told I couldn't because I was already registered.

The Selective Service auto-registers people from various data sources.

But this puts me in a weird spot: I've never actually registered. I am registered. But I did not register - which is the requirement.

There are Kafka-esque parts of the US government where this distinction could matter.