# book6

We must agree on a suitable open source license for this project.

The IETF Trust license for code (Revised BSD License) is definitely unsuitable for a book.

For text, the IETF Trust uses the Creative Commons Attribution 4.0 license, known as CC BY 4.0. See [https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/). At first sight this looks suitable for our book.