<P> Since most of the common people could not read or write, the' X' was placed on documents, and a kiss was placed over it as a show of their sincerity . The Chi Rho, often represented with the letter' X', was also used as a holy symbol throughout Christian history as it represented the Greek word for Christ ΧΡΙΣΤΟΣ; this gave rise to the practice of using the letter' X', which was then kissed in this tradition of displaying a sacred oath . </P> <P> There is speculation on the Internet from at least one original source that the' O' is of North American descent: when arriving in the United States, Jewish immigrants, most of whose first language was Yiddish, would use an' O' to sign documents, thus not using the sign of the cross, and shop keepers would often use an' O' when signing documents, in place of an' X' . </P>

What does x and o stand for in xoxo