Verify book outline translations

Forgive me, but I don't think I have enough context to understand what needs to be done to verify book outline translations. The 8.x-1.x branch is no longer supported: if this still needs to be verified in 8.x-2.x, please change this issue's Status back to "Active", and the Version to "8.x-2.x-dev". Thank you very much in advance for your understanding and patience with me.

I'm going to close this as "Outdated" because the 8.x-1.x-dev branch is outdated and we haven't received a response about whether this task is still needed in 8.x-2.x. (I'm trying to clean up old issues in preparation for a 2.0.0 release, thank you in advance for your understanding and patience)