UnrealIRCd has server-side alias commands. For example
/NS IDENTIFY blah will be forwarded to NickServ of Services. Internally, UnrealIRCd will convert the command to be like /MSG NickServ IDENTIFY blah. You can even make more complex aliases: for example have the /REGISTER command forward the message to ChanServ if the first parameter begins with a # and forwarded it to NickServ if it doesn't.
Aliases are configured in the Alias block.
UnrealIRCd ships with default aliases for anope, atheme and other IRC Services. See the Commonly included files section.