Yours is not the first bag I've seen with this what I had suspected was an aftermarket modification (they all have typically been slim clutch styles), though whoever produced the hole in the one shown did a nice job using a punch and not an awl. Indeed it would be interesting to know who came up with this answer to the question of what to do with the bead chain lanyarded hang tags on bags that do not have straps or D-rings conducive for hanging them from.I previously rehabbed an authenticated slim clutch zipper portfolio 9555 from the 1970s or 80s that has a strange feature which I have never been able to determine as original or a modification? It has a little hole punched in the side of the bag (no grommet) which may be for the hangtag chain. It also looks odd to me but I can't think of any other reason for punching a small hole in the side of the bag, see the pics below. Have any of you ever seen a similar feature on an older coach bag?