One of any number of Pattern Forms. The dominant form on Wiki is Therefore But. And click on The Reform Society glyph at the bottom of this here page for an interesting extension of that.
A Pattern Form is the literary structure of a written description of a pattern. The simplest pattern form is Therefore But. The Design Patterns Book uses a more detailed and structured form. It is interesting to study the pattern form (as opposed to only studying patterns themselves) since the pattern form is a pedagological tool applicable to more than just software and architecture. In other words, "What makes patterns so powerful as a teaching and communicating tool?"
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