For points in a normed space (e.g. complex number,vectors) the notation |z| for the absolute value/length is common. But sometimes one sees ||z|| with the same meaning.

Is there any standard term and notation for the square of such values, preferably one that can be used in plain-text. If not there should be, because in practice they are often easier to calculate and work with.

I'm a computer programmer and would like to have a good name for functions which calculate such quantities. C++ seems to use norm() but that could be confusing.