Strong Concept

A StrongConcept is a Concept that has evolved to the point where it never changes as is it only ever enhanced. At a lower level, its implementation may change but its effect can be depended upon.

A StrongConcept is the generalisation of a particular design pattern and a particular interface.

A particular DesignPattern or a particular Interface is the realisation of some concept.

Correct and useful DesignDocumentation depends on StrongConcepts.

An example is the some sort of transactional pattern to ensure ACIDity. Once the concept (patterns + interfaces) are understood and they are not subject to change then other design entities can depend upon that transactional concept.