https://secure.phabricator.com/book/phabcontrib/article/feature_requests/#describe-problems

I can't really figure out what happened in Phabricator that you would need such a feature, or only need it in Conpherence. We don't have undo elements as a common pattern (its in diff comments only).

Filing feature requests without problems and just a solution makes upstream support very time consuming. We don't want to spend time debating why a feature solution isn't a good fit, and would prefer just to find a solution to your problem. If our "describe problems" documentation isn't clear, what can we do to make it more clear?

Problem: The settings of a Conpherence room were changed mistakenly. I need to undo the change. Resetting Conpherence room images (part of the accidental change) to the default is not possible.

P.S: Since you use transactions everywhere, I assumed they would make the implementation of an undo action rather simple.

If it's not as simple, at least resetting the icon to the default would be helpful. Project pictures have such a feature.

As a temporary workaround, I can upload a new image.

Isn't T8972 the actual core problem. Or if it isn't, can you explain how users need to edit and undo Conpherence Room settings so frequently?

My primary concern is the picture. While I can unset the picture of projects, I cannot do so for conferences. Thus there is no way to return to the original state after something like T8972 (or simply a mistake) occurred.

something like T8972

T8972 is the only reason this task was opened.

(or simply a mistake) occurred.

This is hypothetical. We don't take feature requests around hypothetical scenarios. Please (again) read our documentation on feature requests: https://secure.phabricator.com/book/phabcontrib/article/feature_requests/#hypotheticals