It is critical to KnowYourAudience for every website. Unfortunately, every site I've every site I've ever worked on has at least one HiddenAudience -- people who must be satisfied with the results, even though they are not the targets of the site's communication.
Most often the HiddenAudience is the upper management of the site's owning company. Sometimes it's a broker, and occasionally it's reviewers. The HiddenAudience has the power to torpedo the site, turning it from a success to an apparent failure, but its importance is never mentioned during planning.
It's critical that the design team (at least) drag the issue of a HiddenAudience out and address it. You probably won't be able to eliminate it, and you may not want to bring it up with the sponsor, but by being aware of it, you may be able to take steps to please the HiddenAudience.
It sounds like the HiddenAudience is a force, rather than a complete AntiPattern. What patterns can be used to balance the HiddenAudience force against "positive" forces guiding the design of a site? Do MultipleCrossSections help here? --NatPryce
Agreed, it's probably more of a force. It may be one of the forces working on the proto-pattern TooManyCooks?. --RobCrawford