Green’s Dictionary of Slang

(k)nickers off ready when I come home; an amorous acronym, usu. found on the back of envelopes of love letters (orig. by soldiers).

1999		Guardian 22 July 19: The wartime favourite NORWICH, which I shall not explain in case children read it.
2002		‘Hectic James’ HecticJames.com ‘Stuff’ 30 Sept. 🌐 These are shorthand acronyms used by lovers, such as SWALK for Sealed with A Loving Kiss. Other examples given were: BURMA: Be undressed ready, my angel; EGYPT: Eager to grab your pretty tits; HOLLAND: Hope our love lasts and never dies; ITALY: I trust and love you; NORWICH: (K)nickers off ready when I come home; BOLTOP: Better on lips than on paper (of a kiss).
2024		J. Meades Empty Wigs (t/s) 633: But when he wrote the conventional greeting N.O.R.W.I.C.H. on the back of the envelope the guard became agitated. He was convinced that Freddie was trying to reveal his secret.