Form a strong mental picture of your audience. The acrostic WISDOM, shown in Figure 1.1 on the following page, may help. Figure 1.1. The wisdom acrostic—understanding an audience
EVERY PIECE OF KNOWLEDGE MUST HAVE A SINGLE, UNAMBIGUOUS, AUTHORITATIVE REPRESENTATION WITHIN A SYSTEM.
DRY, you're looking to minimize duplication within a system, whereas with orthogonality you reduce the interdependency among the system's components.