You might want to take a look at pre-existing syntax files for a quick list of reserved words you might want to use-

EditPlus: http://roody.gerynarsabode.org/hugo.stx
Emerald Editor: http://roody.gerynarsabode.org/emeraldhugo.zip
gedit: http://roody.gerynarsabode.org/hugo.lang

[quote]Was creating this to write a syntax highlighter XML script for Programmer's Notepad.[/quote]
Gave some interesting phrases

alias and anything
break call
capital case
children class
do elder
false for held
if in input is jump
locate move
music nearby
number object
picture playback
quit random
remove restart
select serial$
sound string system
true undo

Aww shit, I just busted my entry; this was meant to be a reply, not a replace!

Found them:

alias and anything array at attribute
break call capital case child children class
cls color dict do elder eldest else elseif
false for held hex if in input is jump local
locate move multi multiheld multinotheld
music nearby newline not notheld number
object or parent parse$ pause picture
playback print printchar property quit
random readfile readval recordoff recordon
remove restart restore return routine run
runevents save scriptoff scripton select
serial$ sibling sound string system text to
true undo verb while window writefile
writeval xobject xverb younger youngest