add operator for "only this version"

[jlovejoy]

See discussion here: https://lists.spdx.org/g/Spdx-legal/topic/105846418#msg3552

TL;DR - EUPL-1.1 and EUPL-1.2 have a default position of "or any later version" and if one wants to limit to that version only, they must indicate this. I believe there may be another license with this scenario.

Adding an operator like + to signify only-this-version would provide flexibility for such licenses.

This would require an update to the spec for the license expression annex, but we can begin the discussion here/ on the spdx-legal calls or mailing list

[swinslow]

@jlovejoy I'm not sure I'm in favor of adding a new operator for this use case:

• As you mentioned, it would require modifying the spec. But not only the license expression annex -- also the underlying SPDX 3.0 model (e.g., adding a new class comparable to OrLaterOperator).
• The spec adjustment would also require adjusting tooling to handle the new syntax.
• And, it would likely result in having three different forms for the GPL family of license IDs going forwards:
  1. original style (GPL-2.0, GPL-2.0+)
  2. current style (GPL-2.0-only, GPL-2.0-or-later)
  3. version with new operator (if the operator is e.g. =, then presumably something like GPL-2.0=)

If all of this is just because of EUPL, personally I'd be more inclined to go the -only and -or-later route, for the use cases where this comes up. As opposed to introducing a new syntax element that everyone has to parse going forward. I'm open to discussing it, but that's my immediate gut reaction.

[karsten-klein]

If all of this is just because of EUPL, personally I'd be more inclined to go the -only and -or-later route, for the use cases where this comes up. As opposed to introducing a new syntax element that everyone has to parse going forward. I'm open to discussing it, but that's my immediate gut reaction.

Please not! Btw, in my eyes the '+' extension (to indicate 'or any later version' as pointed out in the spec in D.3 Simple license expressions) is already possible. See https://spdx.github.io/spdx-spec/v2.3/SPDX-license-expressions/:

See line

simple-expression = license-id / license-id"+" / license-ref

[Pizza-Ria]

"+" for "-or-later" either intuitively makes sense or is just so widely used that it practically amounts to being intuitive. Looking at my keyboad, I don't see anything that definitely indicates ONLY so I'd be concerned that a new operator may introduce confusion or mislabelling.