IANAL.

🐰🕳️

Currently the TRs either use the text "MIT License" or refer to http://purl.org/NET/rdflicense/MIT1.0 (or similar as the MIT license template) or possibly something else or undefined.

TRs (and perhaps any other documents under solidproject.org) should link to a human- and/or machine-readable license document that clarifies the rights, e.g., copyright year, rights holder, license.

The solid/specification repository includes LICENSE.md that's using the MIT License with Copyright to "W3C Solid Community Group".

The Solid Technical Reports Contributing Guide's Publication Rules mentions the use of http://purl.org/NET/rdflicense/MIT1.0 .

Participants in the W3C Solid Community Group have signed the W3C Community Contributor License Agreement.

The Solid Project website links to https://solidproject.org/license and that document describes the licenses that are used for its assets.