Tiki wiki uses brackets around words as a way to identify a link.
So typing it normally Tiki Wiki will try to turn the tag into a link instead of showing it as a tag with brackets.
For example [GUILD] will give the result GUILD. Which is fine if you are trying to link to the guilds page.
However , you will need to use two brackets before the guild tag instead of one if you intend on it being displayed as [GUILD].