Location 614:
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
Location 718:
EVERY PIECE OF KNOWLEDGE MUST HAVE A SINGLE, UNAMBIGUOUS, AUTHORITATIVE REPRESENTATION WITHIN A SYSTEM.
Location 967:
DRY, you're looking to minimize duplication within a system, whereas with orthogonality you reduce the interdependency among the system's components.