[Software] TPILB has a very good pedigree. It was used extensively in the 1970s when replacement pages for technical manuals had only half the content of the original, resulting in one blank side right where everyone had hitherto been used to finding text. It was a way of avoiding the (then) expensive customer service calls about non-existent missing text that went nowhere. It also meant that the original contents page would still work, mostly, as the page numbering wasn't screwed up by the change. The only alternative would be to reprint the entire chapter from the change onward which would likely prove to be prohibitively expensive. These days, one often sees such material reproduced either electronically, which makes no sense, or on single-sided copies of the original material, which makes sense but is still odd when you come across it.
[SM] I know, I'm an engineer and at one point in my distant past was responsible for the printing and distribution of technical manual updates (on a subcontract). It still bemuses the uninitiated though.
Ah! Reminds me when I was a technical author myself. I can still take a 20-year-old New World gas cooker to pieces... Just don't ask me to put it together again when I've drawn the pictures.