I recently just developed a batch of film (66 rolls). All the rolls are from my European trip taken last summer, the film was either bought just before (in Japan) or during the trip (mostly in Italy or Prague). All 120 film was shot on my Mamiya 6 (and a couple rolls with my Holga). Of those rolls recently developed, 26 were HP5+. Of those, at least half show this problem. I've noticed four possibilities:
1. The edge markings are even and do not touch the image area. (4219, 4222)
2. The edge markings are uneven in parts, but do not touch the edge of the image area, although for some it just touches the area. The uneven part is usually the batch code number, the "Ilford HP5 Plus" remains even. (4219, 4276, 4222)
3. The edge markings are uneven in parts, and sometimes just touch the edge of the image area, or slightly go over (again, usually the number). It only affects one or two images on the roll. (4238, 4134, 4219, 4276, 4222)
4. The edge markings are uneven, either whole or in part, and some of the markings (both number and text) go into the image area. Sometimes the entire text* is within the image area. (4219, 4256, 4276*)
As you can see, some batch numbers fall into more than one category, and by this I mean that over the entire roll it exhibits only these characteristics. I'm going to go through each roll and do a more thorough analysis and accounting, but this is what I've noticed so far.