I was referring to the rotary press booklet panes not the flat press panes. Some of the rotary press panes show full or partial #'s in the selvedge due to mis-cutting. I was trying to understand the distinction in the Durland catalog appendix listing plate # percentages by position(UL or LL etc...)
Subsequent to my posting, I heard from Kim Johnson who was kind enough to explain that the # position is in relation to the stapled booklet tab. So LL would be on the lower left side of the pane with the tab on top regardless of stamp orientation. Evidently the right positions are very scarce.