There is a chain of pubs or bars in England called the Slug and Lettuce. The unusual name is regarded as a marketing gimmick, but I was reminded of the reason for the Lettuce part of the name when I was browsing through Abram Smythe Palmer's 1882 book Folk-Etymology: a Dictionary of Verbal Corruptions or Words Perverted in Form or Meaning, by False Derivation or Mistaken Analogy.
'Lettuce' is from the word 'lattice' and in the 16th and 17th centuries a red lattice on a sign indicated an alehouse. There are several references to this in the literature of the time. The play Christmas Ordinary, written around the 1680s, and whose author is unknown, has the lines:
'Where red lettice (sic) doth shine,
Tis an outward sign
Good ale is a traffic within.'
In Act V, Scene 2 of John Marston's Antonio and Mellida, written in 1599, is the line:
'As well known by my wit, as an ale-house by a red lattice'.
The lattice-alehouse connection is mentioned a couple of times in Shakespeare's plays. In The Merry Wives of Windsor Sir John Falstaff says to his companion, Pistol (in Act II, Scene 2):
'... and yet you, rogue, will ensconce your rags, your cat-a-mountain looks, your red-lattice phrases, and your bold-beating oaths ...'
Red-lattice phrases being the bawdy language of the alehouse.
In Henry IV, Part 2 Falstaff's page says:
'A' calls me e'en now, my lord, through a red lattice.' (Act II, Scene 2)
'Slug' is an old slang word for a strong drink, or it can be a verb meaning 'swig', so there is an alcohol connection there too.