Re: What licenses should be included in /usr/share/common-licenses?

On Tue, 28 Apr 2026 at 18:44:13 +0200, Timo Röhling wrote:
>In your example, I am a bit uncomfortable with a 
>single, typo-prone "+" sign carrying this much significant information 
>about the license terms.

That's reasonable, and I think the SPDX names like LGPL-2.1-or-later and 
LGPL-2.1-only are better. (If I remember correctly, SPDX originally used 
the Debian-style LGPL-2.1 and LGPL-2.1+, then changed their notation for 
these licenses at the FSF's request.)

With hindsight, having the + syntax for "or any later version" was 
perhaps premature optimization - it seems to be only the FSF licenses 
where this concept is frequently used. Other licenses tend to either 
hard-code the upgrade mechanism in the license itself (like CC-BY-SA and 
MPL do), or not have one.

>I'd like for us to move to a 
>widely used standard of license identifiers such as the SPDX ones

I agree. SPDX didn't exist at the time that copyright-format was first 
designed, but now it does, and it has convenient names for a lot of 
licenses.

I think it would make a lot of sense to align with SPDX, even if their 
names aren't always the names we've historically preferred for each 
license. Notably, SPDX uses "MIT" for "the" MIT/X11 license, 
specifically the one that is used by e.g. Expat, which is neither the 
only license used by MIT nor the only license used in X11 - but I think 
that ship has sailed and "MIT" is a more-widely-understood name for it 
than "Expat".

>We could even adopt the SPDX-License-Identifier: syntax.

I don't think that would be appropriate: SPDX-License-Identifier 
normally means "the license of the file where this marker appears is the 
named license", but in d/copyright the meaning we want is "the license of 
some other file is the named license".

     smcv