I just came across SPDX (https://spdx.org/ids) as part of a discussion on the same topic for Spoon (https://github.com/INRIA/spoon/issues/3158). As far as I understand their goal is to have easier way to discover and made assertion over software licenses, and the easiest for doing that is by using a standardized tag to indicate the license of a file in the license header, such as:
// SPDX-License-Identifier: GPL-2.0-or-later
I’m not quite sure about the benefits for us, but I find it interesting to open the discussion about it.