Passing gpp_sid in url query parameters

[smounitz]

I need clarity regarding passing gpp_sid in url query parameters:

The specs (last line on this page ) say it should be a comma separated string (ex: gpp_sid=6,8) but I see a lot of request with the string enclosed in square brackets (ex: gpp_sid=[6,8])

[janwinkler]

I think the spec is clear here that the value should be a comma list. There is no talk about any [...] and the example URL also does not include any [...]:
http://vendor-a.com/key1=val1&key2=val2&gpp=DBACNYA~CPXxRfAPXxRfAAfKABENB-CgAAAAAAAAAAYgAAAAAAAA~1YNN&gpp_sid=2

Maybe we can make the example more clear for this case and write:
http://vendor-a.com/key1=val1&key2=val2&gpp=DBACNYA~CPXxRfAPXxRfAAfKABENB-CgAAAAAAAAAAYgAAAAAAAA~1YNN&gpp_sid=2,5
(@jaredmoscow @lamrowena )

[janwinkler]

Actually the comma is not websafe and should be avoided. Maybe a spec update could use underscore, dot or minus instead.