Re: AS 3356 (Level 3) -- Community 3356:666

And it's also nice not to yank the old community in case your customers still depend on it, even if you do also support the RFC version as an alias of that one.

That seems to be the case. Also, possibly the use of WKC 65535:666 has not picked up much. We observe that out of a total of 264,557 unique {Prefix, AS Path, Community = Any:666} seen in a whole day's worth of BGP Updates from RIPE-RIS (July 15, 2021), only 21 are with 65535:666. See slide 12 here: https://datatracker.ietf.org/meeting/111/materials/slides-111-grow-bgp-regul... (presentation at the IETF 111 GROW meeting last week) Sriram