non-defining

Technically, the difference here is between a defining and a non-defining clause.

In this case, it is rather formal and is largely restricted to non-defining clauses.

Including non-defining sources, it there are a total of 3414 sources measured using very-long-baseline interferometry.

Cuando tends to replace the use of other relative pronouns when time is referred, usually in non-defining clauses.

It can be used as a formal, emphatic replacement for que in non-defining clauses, for either subjects or direct objects.

The ICRF also contains positions of 396 additional non-defining sources for reference.

If you were puzzled then you have grasped intuitively the difference between a defining clause and a non-defining clause.

Quien is particularly common as the object of a proposition when the clause is non-defining, but is also possible in defining clauses.

However this relation varies according to whether the relative clause is non-defining (as in this example) or defining, as in a student who is a linguist.

(Conversely, non-restrictive relative clauses are called supplementary, appositive, non-defining or non-identifying relative clauses.)

Restrictive modifiers are also called defining, identifying, essential, or necessary; non-restrictive ones are also called non-defining, non-identifying, descriptive, or unnecessary (though this last term can be misleading).

A restrictive, or defining, relative clause modifies the meaning of its head word (restricts its possible referent), whereas a non-restrictive or non-defining relative clause merely provides supplementary information.

It is used, for example, to distinguish between a defining relative clause such as He was waving to the girl who was running along the platform and a non-defining relative clause such as He was waving to the girl, who was running along the platform.