In my experience the pan f+ top and bottom markings are always very faint, I don't know why ilford does that, and I don't like it, but I've never seen defined markings like you would with Kodak films. It's the one thing about ilford I don't like, I'm sure there's a reason they do it, maybe it's an exposure thing where it's supposed to give you a certain color grey when scanned/printed but it just looks wimpy and difficult to see/read.
This was mentioned on another thread where someone stated that the latent image stability of Pan F+ is not very good and it tends to fade with time. This would explain why the edge markings which are a latent image afterall are faint.
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.