X’s and O’s at the end of messages we receive communicate kisses and hugs from the sender, but do you know that there is history behind these abbreviations?  Dating back to the Middle Ages, letters, notes and envelopes were often signed with a cross instead of a signature, as many could not read or write.  On top of the cross the sender would kiss the mark as a pledge of honor and sincerity.  This became a common practice and soon the crosses, which were marked quickly, often resembled X’s.   The O’s symbolic origin is not as clear, but many think that the O shape resembles the encircling arms of a hug.