[SilasX]

>What's unclear or abstract about that? To choose an action, the agent must know what actions are available and how to call them. Whatever presents that information to the agent is the affordance. Fielding says that in hyptertext, you get that as part of the actual content as opposed to via documentation or some other channel.

But then that would be wrong. You had to know, through documentation and other out-of-band education, what you’re supposed to do with these `<a href=...` things. Ditto for any of the other options a page might present.

When you first used the web, you didn’t know what href meant. You had to read some instructions, or depend on UX designers’ decision to graphically represent a-tags in a way that suggests clickability and followability. That’s already outside his REST model.

Fielding is not being clear on how REST’s assumptions about “what you already know out-of-band” differ from other models.