The UML specification book satisfies OCD quite well I'd say.

Page 59, the actual content hasn't started yet, but I'm happy: "Within each clause, there is first a brief informal description of the concepts described in that clause. The clause is then
split into sub clauses, each describing a coherent set of concepts that constitute a portion of the formalism specified by
the clause. Each sub clause is then split into Abstract Syntax, Semantics, Notation, and Examples.
"