Green’s Dictionary of Slang

a lover’s acronym, be undressed, ready, my angel, written on envelopes of love letters.

1999		Roger’s Profanisaurus 3 in Viz 98 Oct. 6: Burma exclm. Acronym used on military correspondence Be Upstairs Ready My Angel.
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).