MongoDB's Server Side Public License is a derivative of the AGPL.

https://en.wikipedia.org/wiki/Server_Side_Public_License

> The Server Side Public License (SSPL) is a very strong copyleft source-available software license introduced by MongoDB Inc. in 2018. It is a modified version of the GNU Affero General Public License version 3.

Wow who would trust a license that is so clearly violating its own license.

Hilariously they provide a diff showing them stripping the copyright https://webassets.mongodb.com/_com_assets/legal/SSPL-compare...

Elsewhere in this thread it was mentioned that the FSF FAQ allows derivative licenses, as long as they have different names.

Yes, they must have been granted another license to copy the license. Presumably this asked them to also remove attribution to avoid confusion.

The license grant is in the FAQ. If it comes down to a legal fight the FAQ is usable in court.