I just checked a bunch of recent vintage Ilford FP4+ and HP5+ sheets in both 4x5 and 8x10. No lettering on any of them. I also found some much older (80s) 4x5 Tri-X 320 negatives. Also blank.
But I've never used any of the TMax/Delta varieties, in sheets or rolls. So the problem here could be mine due to overly narrow sampling. I've also never used transparency films in cut sheets, so 'rorye' could be correct as well.
Maybe I just need to get out more??
I do plan on trying Ilford's 120 Delta 3200 as 6x7, now that we've started our annual 10-month trip through the bad weather tunnel here in the Pacific Northwest.
July is just around the corner...