InspIRCd has been using numeric 650 for reporting syntax issues since 2017. I know numeric 650 and 651 are also used for DALnet's services.

This prints a extra line of reversed colour text "Services Message (sigsegv.teranova.net)" on networks with InspIRCd.

Raw log:
Quote
-> sigsegv.teranova.net whois
<- @time=2025-05-15T09:22:17.246Z :sigsegv.teranova.net 461 KindOne WHOIS :Not enough parameters.
<- @time=2025-05-15T09:22:17.246Z :sigsegv.teranova.net 650 KindOne WHOIS :[<servername>] <nick>[,<nick>]+
Status window:
Quote
[05:22:17] WHOIS Not enough parameters.
[05:22:17] Services Message (sigsegv.teranova.net) <--- Colours are reversed.
[05:22:17] WHOIS [<servername>] <nick>[,<nick>]+

https://github.com/inspircd/inspircd/commit/5a3f8af9f963b164832fabc1163611a2b768a890