Most likely it means "paperback". It could also mean "perfect bound", a particular style of paperback.
The symbol Pb stands for the chemical element Lead, which is a heavy metal with the atomic number 82.
Pb in chemistry stands for Lead, an element whose name in Latin is Plumbum (hence, Pb).
In the Penetrant PB B'laster, the PB stands for Penetrating B'laster.
Pb=Lead
the publisher: Bloomsbury Publishing (UK)
Pb
I know that PC stands for Horizontal-Vertical; although I am Unsure about pb.
EB stands for Earnings Before interest, taxes, depreciation, and amortization, a financial metric used to evaluate a company's operating performance. PB typically stands for Price to Book ratio, a valuation metric calculated by dividing the company's stock price by its book value per share, indicating how the market values the company in relation to its net assets.
Pb is the symbol for lead.
lead dioxide
TIFF stands for Tagged Image File Format :)
Pbteen stands for potery barn teen.