My rims have a couple of small holes along the edge of the flat at bottom of the bead (just above the valley). I assume they are there to vent the space between the tube and the tire, i.e., to let air out as the tube is inflated, but I don't see why that should be necessary. Maybe they are manufacturing artifacts?
The holes are small -- about a 0.1" (2.5 mm) in diameter. Should I cover them with rim tape to protect the tube? That will require wider rim tape--wide enough to get into the bead area. Seems bad.