Many of the OperServ commands are listed in the OperServ help files however they are issued with different services agents such as NickServ or ChanServ, the reason why they are listed under OperServ is because you need OperServ access to issue these commands. OperServ access levels are Services Administrator also referred to as SA, ChanServ Super Op aka CSop, and root administrator.

@SHUTDOWN - Will Shut down services.
@UPDATEDB - Will update Nick, Chan, and OperServ Database.
AOP - Modify AOP lists for any room.
AUTOKILL - Set permanent akills on large domains.
FORBID - Prevent registration of certain nicks or rooms.
HELP - Get help on root commands.
JUPE - Prevent servers from connecting to the network.
KEEP - Prevent a nickname or room from expiring.
LOCKPASS - Stop a password from being viewed by CSops.
OPER - Accessing Operator Prviliges through OperServ.
OPERCFG - Network operator configuration additions and changes.
PROTECT - Make a room be protected by network services.
SENDMEMO - Send a memo to all registered nicknames or to all room founders.
SOP - Modify SOP lists for any room.
UOP - Modify UOP lists for any room.
VOP - Modify VOP lists for any room

/os help root <topic>