[Gemini]

I've looked it up for ya, and heres what I found;

myriad is to enable some "Myriad Islands" mod. Dont know exaclty what they are...
nosign seems to be a useless command, with no purpose
query is some command that has to do with UDP protocols..
thats all I could find sorry.

Well if I saw some strange looking commands on the /rcon cmdlist, i wouldnt try them, you never know it might blow up your server.