How about:
"External links are allowed, provided they are relevant to the discussion and do not link to material that would violate the forum rules. In particular, links to the following types of resources are generally acceptable:
- Articles related to the topic
- Product pages
- Parts lists (although a more forum-friendly format is recommended)
- Product reviews and analyses
Inappropriate links may be removed by the moderators."
The glitter made it
that bad. Nothing good has ever resulted from glitter.