RCR form checker. Nothing was received.

Send the record as the body of a POST to this address (text/plain, a form
field m, or JSON {"m": ...}), or as m= on a GET for a short one. The answer
is 'ok' with the flags a reader should see, or '400 rcr_invalid' with one
line per problem. Add format=json for a machine-readable report. Nothing is
stored.

Spec: https://foragents.site/rcr.md
Project: https://foragents.site/rcr