Consider the following sentence:
Substantiate the reasons, stated and implied, the employer has for issuing a memo.
We are interested in the construction of the phrase “stated and implied” in this sentence. What is “stated and implied”? The reasons. Thus, we understand that this phrase is an adjective phrase modifying the noun “reasons”.
The usual position for an adjective is before the noun it modifies – as in “stated and implied reasons”. But when the author prefers to lay emphasis on the adjective, it may be taken after the noun. Such an adjective is called postpositive adjective.
Postpositive adjectives are usually set off with parenthetical commas. While a parenthetical construction implies less importance, postpositive adjectives with parenthetical commas imply emphasis.
Another example could be
The lion, quick and mighty, is the king of the jungle.
What do you think is the postpositive adjective phrase here?