wss://relay.mostr.pub/?broadcast=false

nostr:npub108pv4cg5ag52nq082kd5leu9ffrn2gdg6g4xdwatn73y36uzplmq9uyev6 is this a standardized parameter? I saw it on nostr.band and <https://docs.nostr.wine/filter/readme> but I can't find any info or code for it in strfry or anything.