These are:
They follow the same basic MLA citation format, however, you may not have all the regular elements. If, for example, you don't know the date you would leave it off.
Some examples are:
Materials, such as an assignment prompt, given to you in print in class or uploaded to your learning management system (Canvas) are only available to you and others in your class. Since they were not published and are not readily available to others, include details to help clarify that.