Can GPLv3 packages be synced?

[Stephen J. Turnbull]

Mats Lidell writes:

 > I checked a few 21.5 files in the src folder and found them to be
 > GPLv2-or-later-at-your-option.

No, that's all that needs to be done.  If we find a file that is not
v2-or-later, then we need to think about what to do.

 > But I fear that such a simple
 > identification is maybe not enough!? What else can influence if
 > promotion is possible?

AFAIK all licenses that can be promoted to GPLv2 can also be promoted
to GPLv3.  I don't think there's anything to worry about except files
that say they are GPLv2 and not later.