When you're writing an article for WWWiki, consider the audience you're writing for. Since WWWiki is intended primarily for White Wolf fans, readers are likely to already be familiar with the basic premise and setting of the subject. However, it never hurts to be too careful, so specifying the appropriate series (or at least the century) is encouraged, so that the topic can easily be placed.
Be sure to explain jargon in most cases — not everyone has memorized the entire library of WW books or is familiar with all the rule system terms that the books use!
The most important goal, however, is to make the article readable and informative. Towards that end, you should do whatever you feel is necessary to make the article meet those standards.
See also: Inform and entertain