I highly doubt that this reader was actually reading a book in Old English because (1) the OED's first citation for the abbreviation "&c." is in 1418 (Old English is only thought to have extended into the 1100s) and (2) if he or she had actually been reading a book in Old English, trying to decipher a random Latin abbreviation would have been the least of their worries.I was reading a book in old english and at the end of a letter the person signed it as &c.
For future reference: Old English looks like this:
For what it's worth, the OED also says this:Fæder ūre þū þe eart on heofonum, sī þīn nama ġehālgod.
That covers &c. in a salutation, so I'm guessing that &c. at the end of a letter is similar in nature (as the Board writers suggested).A custom formerly common, but now nearly disused except in certain government offices, is to write ‘&c., &c.’ in the addresses of letters, as a substitute for the titles of office or dignity affixed to the name of the person addressed.