This is not a question about whether a priest can reveal anything regarding a specific Confession; clearly the answer for that question is no.
However, is a priest allowed to reveal if certain sins have ever been confessed to him? For example, if I asked a priest, “Have you ever had someone confess to murder?”, and not inquiring about any identifying information - church, date, etc. - would they be able to say yes or no?
However, is a priest allowed to reveal if certain sins have ever been confessed to him? For example, if I asked a priest, “Have you ever had someone confess to murder?”, and not inquiring about any identifying information - church, date, etc. - would they be able to say yes or no?