If part of the data is just a random number like a UUID that is meaningless to a human, well that number could simply be placed after the pixel-font text or as a rectangle outline...if using a 3x5 pixel font then that gives 4x5=20 bits per character cell, so a 128-bit UUID with 12 bits of overhead could fit within the space of 7 characters...fine...but at least put the parts of the info that the human can relate to (like that this a MENU for RESTAURANT) as pixel text so both the human and machine are happy.