overall syntax / authoritative list of attributes

[olivierthereaux]

The naming syntax makes mention of some attributes being mandatory (or _ as a minimum_) and others as optional.

• if this language reflects "common usage" we should make it clearer
• If this language reflects the fact that there is a full list of such attributes, with some being mandatory and other optional, then the document could list those, and make it clearer for systems implementing the syntax which properties they should expect/require.

[olivierthereaux]

This also makes me wonder whether there is a recommended representation (or a number of those) for the representation of all the properties of a device. Given examples in the document I presume that is standardised elsewhere and out of scope, but this could 1) be clarified and 2) we could add pointers to established standards?