omissible

The remaining 75 minutes was omissible but few at Villa Park cared about that.

Comment modifiers are syntactically omissible in that the omission of one leaves a complete, well-formed unit of structure; and they are textually omissible in the sense that the omission of one does not affect the ability of the reader to identify the denotatum of the head noun or antecedent element.

On a methodological level, Coveney proposes an interesting threefold typology of grammatical variables: omissible items (such as ne), alternating items, and alternating structures (for example, interrogatives).

The postpositions which designate the search domain and the general locative preposition are omissible under certain conditions.

Adjuncts are usually freely omissible, but in Awa Pit and Songhai the omission is mandatory.

In the following example, I have put square brackets around omissible material (as usual, any of the noun phrases are omissible on their own):

The adverb taare is omissible only when the copula naa is followed by a locative adverb, as in: yanaa can (taare) da baakii 'he is there (together) with the guests'.

In English (and also at least in Swedish, German, and Finnish) the Benefactive/Source is freely omissible, which means that three of the four roles are conceptually prominent.