MET CUST WOM

I often have different things shipping to me, and so I get fairly familiar with the systems of FedEX, UPS, DHL, and the post system. One thing that has recently confused me, though, is a note I infrequently see on the UPS site after deliveries: MET CUST WOM

The 'WOM' part is what confuses me. I haven't been able to figure out what that's an acronym for. I've only seen it maybe two or three times, the most recent time yesterday on the delivery confirmation for the new power supply for my desktop, but it's always been a mystery. The last time I remember seeing it, that I can think of, there was nobody actually at home when the delivery person tried stopping, but then someone got home soon after, grabbed the tag they left, and went to flag down the delivery person in their truck as they were usually still in the area. So my guess is the first to letters stand for 'While On', but the 'M' has still eluded me.

So anyway, my desktop is back up now, but strange things are still afoot. I think I have things stabilized for now, but it's problem makes less and less sense with each step I take.