Hidden message

Information that is not noticeable

A hidden message is information that is not immediately noticeable, and that must be discovered or uncovered and interpreted before it can be known. Hidden messages include backwards audio messages, hidden visual messages and symbolic or cryptic codes such as a crossword or cipher. Although there are many legitimate examples of hidden messages created with techniques such as backmasking and steganography, many so-called hidden messages are merely fanciful imaginings or apophany.

This keyword could refer to multiple things. Here are some suggestions: