Small potential erratum

Another small item I just noticed, the wording in the cookie discovery
profile (Prof 4.3.1) is a bit ambiguous, unfortunate transfer of text from
ID-FF that didn't reflect the profile's changes.

The intent (at least my intent) was that the cookie contain a delimited list
of providerIDs, then the whole list base64-encoded, and then URL-encoded:

URLEncode [ Base64 [ providerID providerID providerID ] ]

The way it reads it sounds like each ID is base64-encoded, then the
separated by spaces, and then URL encoded:

URLEncode [ Base64[providerID] Base64[providerID] Base64[providerID] ]

The original profile had binary data (the SourceID hashes) so each value was
encoded first, I think, but we tried to simplify things.

Obviously the second way is dumb, bit it definitely reads that way. So the
erratum is up to the TC I guess. But we should clarify it either way.

-- Scott