What is FPS for?

[martinthomson]

In #53, it seems like a lot of the discussion is cross purposes. It seems like there are a number of different ideas floating around and it is hard to make progress in those conditions.

It seems like there is an almost deliberate attempt to avoid defining a singular purpose for FPS. That is, the purpose of FPS seems to be something that different browsers decide on their own.

I'll credit @annevk with this analogy, though he used it in a different context: there is a switch that we know how to turn on and off, but we don't know what it is hooked up to.

If this switch is not hooked up to the same thing, that a failure of this process. The entire point of incubation is so that we can agree to work toward a common goal.

I thought it might be worth examining the stated goals more closely, but I didn't find those helped answer this question for me.

1. Allow related domain names to declare themselves as the same first-party.

This is a means, not an ends. For this to be a goal, we would need agreement about what being "first-party" means.

2. Develop a coherent definition of "first-party" vs "third-party" for privacy mechanisms on the web platform.

Ah, there it is. That's a good goal for a specification, but it doesn't really say anything about the goal of the mechanism that is being specified.

3. Allow for browsers to understand the relationships between domains of multi-domain sites such that they can effectively present that information to the user.

This is, I think concrete enough to act on. But it's fairly clear from the other points, along with the swathe of other proposals that refer to FPS, that this is not the entire picture.

(FWIW, I'm not trying to be disingenuous here with the question; I think that this ambiguity is really harming attempts to make progress toward any sort of resolution. I might not like FPS as proposed, but that could just due to a poor assumption on my part. Discussion on #53 showed that there is a much wider diversity of assumptions than I had expected, so I thought it worth clarifying.)