Add SPDX tags and link to specific version

[marbre]

No description provided.

[marbre]

@swltr as discussed offline.

[maxhoerstr]

I was wondering if it's possible to assign two licenses to a single file? Also, could you explain why we use CC-BY-3.0 instead of 4.0? If I've understood correctly, the Apache-2.0 is the license from the Google styleguide, and the CC-BY-3.0 is for our changes.

[marbre]

I was wondering if it's possible to assign two licenses to a single file? Also, could you explain why we use CC-BY-3.0 instead of 4.0? If I've understood correctly, the Apache-2.0 is the license from the Google styleguide, and the CC-BY-3.0 is for our changes.

You can have the legal obligation to comply with two licenses and that's what the conjunctive "AND" operator is intended for.

Furthermore, we don't decide which licenses we need to comply with. CC-BY-3.0 is mentioned in the Google repo, see google/styleguide#637.

[maxhoerstr]

I was wondering if it's possible to assign two licenses to a single file? Also, could you explain why we use CC-BY-3.0 instead of 4.0? If I've understood correctly, the Apache-2.0 is the license from the Google styleguide, and the CC-BY-3.0 is for our changes.

You can have the legal obligation to comply with two licenses and that's what the conjunctive "AND" operator is intended for.

Furthermore, we don't decide which licenses we need to comply with. CC-BY-3.0 is mentioned in the Google repo, see google/styleguide#637.

Alright, then everything is looking fine to me :)