harris first described forwarding by relating it to his email program. the <-- was for sending comments back to the sender, but the --> "directs them out to other readers." then he goes on to say that, "a writer forwards a text by taking words, images, or ideas from it and putting them into use in new contexts." he then proceeds to break forwarding down into 4 types, illustrating, authorizing, borrowing, and extending.

Illustrating is for when you are trying to make a point. you go and look for examples where other people have made the same or a similar point. Authorizing is when you use drawl upon the expertise or status of another writer in order to support your writing. borrowing is when you use the terms and ideas of other writers in the process of thinking through your subject. extending is when you take terms or concepts from someone else and use them in a different way the the original user.