left blank my miftake

I often seen pages in books which are blank except for the self contradicting phrase "Intentionally Left Blank" or words to the same effect. I understand that for page layout purposes knowing that the page should be blank could be useful, although I've never understood the need for the words in modern day printing.

Now I've no idea where the idea of placing something on a blank page originates but I like the following explanation offered up by Simon Wheaton-Smith in the BCS Computer Bulletin.

Back in December 21 1797, in the manor of Romburgh in Suffolk, things were done then as they probably are now, slowly, and in a gentlemanly fashion and they held their manorial courts of custom. Property was held back not only by freehold and leasehold, but also by copyhold. And so it happened that when a copyholder died the required court of custom convened, and the heirs, a family called Wade, were summoned to pay the fee for the transfer of the copyhold.

The steward of the court convened the session, but no one was present. The process was repeated, and as lunch-time approached, still no heirs. And so, based on the handwriting that I have analysed, the court went to lunch, and it must have been at a pub, where they must have had some libation. They returned in a jollier frame of mind and closed the court to the satisfaction of all concerned, especially a John Wade, successor to the copyhold. However, in retrospect, the steward of the manor noted he had left a blank page in the court record, which was a no-no.

And so, in beautiful script, penned in a multi-line diamond shape, are the words: 'left blank my miftake'.

In those days the s was an f except in the last letter of a word.

And so, from the distant recesses of time, that evolved into a more face saving expression: 'this page left blank intentionally'.