The term 'cartridge content' refers to the material stored in a cartridge, which is a device used to store and play audio or video recordings. The two crossword solutions for this term are 'INK' (3 letters) and 'stereotape' (10 letters). INK is a liquid or paste that contains pigments or dyes and is used to color surfaces or to create an image. Stereotape is a type of magnetic tape used for recording sound, typically in stereo.