Opinion of the Court
The Court held that nominative use (a type of fair use for discussing the product itself) is permitted where:

The product or service can not be readily identified without using the trademark (i.e. trademark is descriptive of a person, place, or product attribute);
Only so much of the mark is used as is necessary for the identification (i.e. the words but not the specific font or logo)
The user does nothing to suggest sponsorship or endorsement by the trademark holder - which applies even if the nominative use is commercial.
The Court found that the same test applies for metatags, and that if a use is found to be nominative, then by definition it can not dilute the trademark.

In this case, the Court found that Welles could not identify herself without using the trademarked terms – the PMOY was something Welles was awarded, so she needed to use the term both on the site and in the metatags to identify herself as a recipient of the award. Furthermore, Welles used no more of the trademark than the words themselves (which is as minimalist as is possible) and disclaimed any endorsement from Playboy. Only the wallpaper (which was, itself, nothing but the term repeated over and over again) was not nominative.