I see in the repository that there's a hidden config for a ratings system:
[*= system.rating_enabled ] Distributed reputation reporting and data collection. This feature is currently being re-worked.
Digging into the code a bit, I see this:
ratings are gone. They can be enabled, but there is no UI for doing so at this time; and will likely only be available in a 'pro' configuration once the new implementation details have been hashed out. This appears to require a mechanism for rebuttal before it can again be opened to the public. There are also some synchronisation issues to contend with; as ratings are currently only distributed to active directory servers. There is no reliable mechanism for a new directory server to fetch existing ratings.
More on the directory issue here: https://github.com/redmatrix/hubzilla/issues/406
If someone has time, can they explain how the ratings system were supposed to work? Also, if there's currently a discussion happening somewhere about the nature of a future ratings system, I'd be grateful for a pointer.