Several railway officers have assured me that a standard opening in railway official correspondence is: ‘Dear Sir, with reference to your above see my below’.More here.
Below can be used as a adverb: go below the deck; we saw the blue waters spread below us. But in IE we see the use of below as an attributive modifier of a noun — the below statement.
Xu Wenkan is well known to readers of Language Log, both because he was
memorialized in an obituary here — "Xu Wenkan (1943-2023)" (1/10/23) — and
because ...