[@chrishajer Participant 19 years, 1 month ago]

I think this feature was removed from the core and added as a plugin:

https://bbpress.org/plugins/topic/16?replies=1&more=1

Not sure from the release notes if this works with .81 or not, but I imagine the functionality will still be there, just in plugin form, not in the core. I think there were more requests for it to be out than in.