command: command
argument: (optional) an existing command, or  
 
Executing command with an already existing command alias as a parameter 
will remove that alias.  Using it with   will create a 
new alias for  which is defined as .  Using command with 
no parameters will list your currently defined aliases.
 
How command works:
  Command-aliases replace words in commands; it will not replace 
  arguments. For example, if you have a command alias for 'la' which 
  redefines it as 'look at' when you type 'la dog' you will execute 'look 
  at dog' instead.  This does not mean if you have a command alias 'foo' 
  for 'power blast' that you can type cast foo to cast power blast, use 
  "alias" for this function.

This all sounds a bit confusing, but really it's quite simple.
Here's an example of using command in conjunction with alias:

  command z cast SPELL at TARGET    Creates a quick-key command 'z'
  command tar alias TARGET	    Creates a quick command to change
				    your target.
  alias SPELL power blast           Makes your primary spell cast
			            'power blast'
  tar frog			    Sets TARGET to 'frog'
  z				    Typing 'z' will execute the full 
				    command which reads as: 'cast
				    power blast at frog'
 
To remove a single command simply type command .
  IE: To remove a command called 'z', type 'command z'. 

To remove all commands at once, use uncommand.
 
See also 'alias', 'uncommand', 'chain'.