Warning! The Scrum Patterns Prime Directive:

Patterns are not a concrete methodology, and using only documented patterns is a sure fire way to destroy creativity and innovation. These patterns are not an official part of Scrum in any way -- they're just ideas. So… use the patterns with care, and don’t forget to be creative. Mix and match, combine, tweak, create a new pattern, or don’t ever hesitate to use your own technique that doesn’t resemble an already existing pattern.