Note that this are not rcon commands but admin commands. Rcon commands can be any cvar here is an example;
rconpassword "password" - to login.
rcon "cvar" - etc: rcon g_gametype <value> etc...
While admin commands would look smth like:
/login "password" - to login
!restart - In chat, note that command availability is depended what level admin has and what commands owner of server assigned to that level.
Alternatively, you can try !list_cmds and if it's enabled by server, it will print all commands admin of that level can use...
To see what command does, replace ! with ? like etc ?restart
One thing you should note and understand, rcon is much more powerful since it can change any aspect of game and even kill it or crash it etc..so use it with caution as well as don't give it all around. For most of common commands, you can set in admin settings, any specific command can be assigned to any admin level by adding it to appropriate level a?_cmds cvar..for etc level 1 in a1_cmds ..you can add in any of the admin commands listed on page as well as cvars if you want like g_allowVote etc..that way you control what admin of that particular level can do and use as well as if g_extendedLog is enabled, trace admin actions easily since for rcon log you need to go thru lines of log to find it etc..
Hope it's clear, if not read the page I wrote about admining and fretn posted above.