Pb typically stands for "paperback" in book format, indicating a less expensive, softcover edition. Hardcover editions are often denoted as "Hb" for hardback.
Most likely it means "paperback". It could also mean "perfect bound", a particular style of paperback.
The chemical symbol Pb stands for "lead", Plum bum.
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)
I know that PC stands for Horizontal-Vertical; although I am Unsure about pb.
Pb is the symbol for lead.
lead dioxide
TIFF stands for Tagged Image File Format :)
Pb
Pbteen stands for potery barn teen.
"Cis"