> The Go trademark and the Go Logo ( ) – collectively, the “Go Trademarks” – are trademarks of Google and are treated separately from the copyright license grants contained in the BSD-licensed Go repositories, as described below.

> Substantially unmodified distributions¶

> Substantially unmodified distributions may use the Go Trademarks if the derivative work complies with the terms of the Go programming language’s open source license and is made in a good faith attempt to replicate the quality and substance of the original project.

> Examples of modifications that would be considered substantially unmodified include language translation and localization, bug and security patches, and necessary interoperability/compatibility modifications.

> The Go Trademarks may be used in connection with such substantially unmodified distributions following the “Naming Conventions for Authorized Uses”.

> Substantially modified distributions may include explicit changes to functionality, interfaces, or features.

They can modify these trademark terms later too with a "backwards incompatible" change:

> Guideline Version¶

> These Trademark Guidelines are version 1.0 and may be followed by subsequent versions. These Guidelines may be edited for clarity; the major version will be increased when changes introduce new requirements, define new criteria, or otherwise present a backwards incompatible change.