Make sure you put your Text Book Zero language in your syllabus and in the message portion of this syllabus archive. (If you need assistance with TBZ contact Brian Newberry email@example.com).
For example, wording like this should be in your syllabus and here in the message here you post your syllabus.
Text Book Zero - The textbook is available in a digital format and may be purchased in the bookstore.
Here is an example of what your message should look like: