Guild Wars Wiki:Guidelines

A guideline is an instructive page like a policy, but only represents a common suggested approach rather than a consensus decision. As guidelines do not necessarily represent a community consensus, they are much more open and easy to change, and are not to be enforced by administrative action.

Role of guidelines
Guidelines fulfill the role of establishing conventions. These are not laws that bind editors of the wiki, but useful agreements that make everyone better off if followed. For example, regulating the formatting of a specific type of article makes the wiki more accessible to the user and easier to edit for editors, yet such a regulation can easily be changed if any other form of formatting is deemed better by anyone. As such, guidelines serve to channel discussions and facilitate easier consensus on a large number of articles, yet they are nothing more than that: An "easier to read" form of discussed conventions.

Establishing a guideline
Before establishing an article as a guideline, gathering a consensus in discussion is strongly encouraged (but not required). For convenience, it is required to tag guidelines with the guideline template.

Changing a guideline
Unlike policy, there is no formal mechanism to change a guideline. To be specific: Just like all normal wiki articles, guidelines can be directly changed by anyone. Of course, it is advisable to discuss controversial changes on the talk page first, but this is not required.