The role of a trainer or consultant is to empower the customer, not to make himself indispensable

Correctness is clearly the prime quality. If a system does not do what it is supposed to do, then everything else about it matters little.

Constants are widely known for the detestable practice of changing their values; we should prepare ourselves against the consequences of such fickleness

Incorrect documentation is often worse than no documentation.

The role of a trainer or consultant is to empower the customer, not to make himself indispensable

Software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification.

Perfect reusable components are not obtained at the first shot.