Wikipedia the Font of All Knowledge wrote:The word ditto comes from the Tuscan language, where it is the past participle of the verb dire (to say), with the meaning of “said”, as in the locution “the said story”. The first recorded use of ditto with this meaning in English occurs in 1625. Early evidence of ditto marks can be seen on a cuneiform tablet of the Neo-Assyrian period (934 – 608 BC) where two vertical marks are used in a table of synonyms to repeat text, while in China the corresponding mark is two horizontal lines (二);
After time served mucking out the ADM stables, DM Ditto is promoted from a typographical symbol to the heady heights of Mount DM, where she sips the nectar and ambrosia of greater responsiblity (to think up fiendish ways to make the lives of PC's difficult!)
Good luck!