Hi Philippe,

SPDX-License-Identifier: .com.amazon.-.ASL-2.0
https://aws.amazon.com/doc/ASL-2.0

[...]

In a SPDX-License-identifier declaration, a Private License Identifier
can optionally be followed by a URI pointing to the canonical license text.
This URI should be under the control of the entity that controls the
DNS namespace of the Private License Identifier.

SPDX-License-Identifier is not declaring an id, but instead using ids in an
expression so I think this would break the license expression syntax may be?
Otherwise how would express something such as:
my-private-license1 AND my-private-license2

[G.O.] Good point on the license expressions. Including the URI expression in the license expression would make it difficult to parse. I suggest we separate this into 2 proposals. One for a standard mechanism for defining a namespace within the licenseRef ID syntax and a separate standard way of describing the URI for either a license-XML definition and/or canonical license text.

For referencing the URI for the license XML or license text, we could extend the license expression syntax with additional operator(s). For example:

License-ref1 DEFINEDBY https://some.uri/with/licensexml

If we take this approach, we would need to do some additional work to define the operator precedence and think through the compatibility issues. I can foresee a few issues with the above proposed approach but I thought I would put it out there for consideration.


Gary