What is Responsible Users in Phabricator Differentials?
Go to Differential -> Advanced Search in Phabricator
The first field in the query form is "Responsible Users". What is it for?
I couldn't figure out for which diffs I'm responsible... even if I'm on the reviewers list or a project reviewer of a diff, some of my reviews are not listed when I execute the query.
Solution
I believe that it depends on the state of the diff:
If the change is waiting for review then the reviewer(s) are responsible.
If someone requested changes then the author is the responsible user.