In the blockchain this means:
(example) reply 6d03
= OP_RETURN output plus an output to address funding MEMO or MEMBER or gateway servers.
FreeMarkets.Cash uses similar for advert
Which resembles why my previous post, a send 'Memo "Action" code' that carries 217char string payload plus paying to someone, sendable but not front-paged unless to 'you'.Which in the special case of fees to Member (or Memo) (or whatever gateway server) displays the post front page. While funding these vitally important projects continued prosperity.