proposed minor change to section 5 schema rules

The P3P Specification Working Group has been discussing
the #dynamic data element. We realize the spec is 
somewhat vague about whether it is legal for
a policy to refer to #dynamic by itself (rather than
#dynamic.clickstream, #dynamic.miscdata, etc.), and
if so, what category rules would apply. We have only
found two P3P policies that do refer to #dynamic,
and both appear to be doing so in error. We believe
the easiest way to clarify things is to make it illegal
to refer to #dynamic in a policy. So we are proposing
the following changes. We do not believe these
should cause a problem for anyone. But if they do
please speak up ASAP and let us know your concerns.

Add the following right before 5.3.1
(this is not really necessary, but helps clarify):

"A data schema may include multiple
DATA-STRUCT elements that together
describe a structure. For example,  there is no
single DATA-STRUCT for the uri data structure in the
P3P base data schema. Instead
uri.authority, uri.stem, and uri.querystring
are interpreted together to define this structure."

Then in 5.3.1 we need to add a 9:

"9. A <DATA-DEF> with some variable-category
elements and some fixed-category elements MUST
NOT be referenced. (Note, this means that while
the #dynamic element implicitly exists in the base
data schema, it cannot be referenced in a policy.
Each of its children -- #dynamic.clickstream,
#dynamic.http, etc. -- can be referenced individually.)"

Also an error correction for number 8:
it should be "sub-elements of a structure" not
"sub-elements of a category"

Lorrie Cranor

Received on Tuesday, 16 October 2001 16:59:00 UTC