What’s your definition? Here’s theirs: > Our FontCode system embeds in a text document any type of in- formation as a bit string. For example, an arbitrary tex

What’s your definition? Here’s theirs: > Our FontCode system embeds in a text document any type of in- formation as a bit string. For example, an arbitrary text message can be coded into a bit string using the standard ASCII code or Unicode. We refer to such a bit string as a plain message. In a text document, the basic elements of embedding a plain message are the letters appearing in a particular font I think you’re talking about the plain message. There’s nothing wrong with their definition of text document.