Optative in a sentence as a noun

For you dog owners living there: Is parvo vaccine optative in Norway?...

Optative in a sentence as an adjective

Armisael's comment is not optative; he is not saying that we should be doing something because it has been done in the past, but providing an example of when something was done in the past.

Optative definitions

noun

a mood (as in Greek or Sanskrit) that expresses a wish or hope; expressed in English by modal verbs

adjective

indicating an option or wish

adjective

relating to a mood of verbs in some languages; "optative verb endings"