Actually, word around the agora is that penance is a real possibility. As to what kind of infraction would warrant such, I don't know, I haven't been curious enough to ask. Nor have I been naughty enough to find out the hard way. And I don't know what all is entailed. But I do know that those under penance are barred from communion for the duration. So it would have to be a rather weighty matter, comparatively speaking.
You're right. I was focusing on the three Hail Marys stuff and forgot about this. I may have been naughty enough, I suspect, but I guess the confessors took pity on me. Actually, what happens is that the penitent is told to do something, or refrain from doing something more likely, and during some period of time, he or she might be barred from communion. An instance might be when a couple is living together without being married. The priest refuses them communion, tells them that they msut come to confession and one or the other is sleeping on the couch until the wedding; in the meantime, no communion.