This is a GUI so players can set their own rank (prefix), and not be limited to roles, etc
Code:
cmd create rpranks Get a custom RP Rank
cmd add rpranks %player% = %p%
cmd add rpranks if varset(%args%[1]) then %player% = %args%[1]
cmd add rpranks %gui%["type"] = "custom_form"
cmd add rpranks %gui%["title"] = "Enter your RP Rank"
cmd add rpranks %item1%["type"] = "input"
cmd add rpranks %item1%["placeholder"] = "Whatever you wish to RP as!"
cmd add rpranks %item1%["text"] = "Enter your RP Rank"
cmd add rpranks %content%[] = %item1%
cmd add rpranks %gui%["content"] = %content%
cmd add rpranks %response% = dialog(%player%, %gui%)
cmd add rpranks if varset(%response%) then message %p% Your rank has been set!
cmd add rpranks if varset(%response%) then goto 14
cmd add rpranks exit
cmd add rpranks let %rank% = join(%response%, \" \")
cmd add rpranks asop /setprefix %rank%