Name for $N^T A N$ when N is rectangular?

Question

According to wikipedia, a transformation of the form

$$A → P^T A P$$

is called a congruence transformation when $P$ is invertible (and thus square).

I often run into transformations of the similar form

$$A → N^T A N$$

where $N$ is rectangular.

For example, this happens in optimization when $x^T A x$ defines a quadratic objective and then $x = N y$ is substituted to reparameterize over a linear (sub)space (e.g., enforce linear equality constraints).

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