47. The computer readable medium encoded with the computer program of claim 42 , wherein: the string includes one or more references comprising one or more out-of-band values not defined in an encoding standard.
50. The computer readable medium encoded with the computer program of claim 47 , wherein: identifying a glyphlet based on the identified reference includes identifying one or more target attributes based on the identified reference and identifying a glyphlet in a collection of glyphlets based on the identified target attributes.