The forgotten assignment operator “=” and the commonplace “:=”

Question

The documentation for PL/pgSQL says, that declaration and assignment to variables is done with :=. But a simple, shorter and more modern ^{(see foo}

Answer 1

Reading the Postgresql 9 documentation:

This page lists "=" as an assignment operator in the table on operator precedence.

But strangely this page (assignment operator documentation) doesn't mention it.