The Ninth point summarizing my longer explanation of the PMW says:
“Unofficial or private use of the keys” describes those times when individual Christians speak for Christ, giving His forgiveness to sinners without having received a regular call to do so. Though it is called “unofficial” or “private,” such an act is really public in the sense that Jesus has given Christians the authority to do this in times of special need. In effect, the individual Christian is acting as the pastor of the one being forgiven.
Personally, I would prefer that our use of terms like “public/private” and “official/unofficial” were more consistent. Such things are hard to standardize, so we end up needing to clarifying the sense we mean almost every time we use them. This makes our expressions more unwieldy, but maybe it has the advantage that the uninitiated can more easily understand what we’re saying, as long as we explain what we mean sufficiently.
I think this point is pretty self-explanatory. Let me know if you disagree.