P.R.C.= Peoples Republic of China?
Has to be.
My guess is the marketing folks know there's a segment of buyers that China would catch their attention.
For belts it should be pretty easy to cross reference to other brands.
If they've moved hoses to a different plant, I'm going to be a little bummed. I've found different companies hoses are often a little different even though they cross reference as the same. Its been good to have a choice when trying for the best fit.
Dayco Belt Numbering
Dayco part number for v-belts consists of nominal top width followed by effective length.
For example. 15480 is 15/32 wide, 48.0 inches effective length.
(If we measured the outside, the book shows 48.6" overall length.)
For LA engines with the later water pump and pulleys:
Non-a/c, non-p/s LA engine Dayco lists a 15475.
Chrysler books show a belt listed as 47.76" O.S.
For the pre 1970 LA water pump and pulleys Dayco lists the 15470 belt.
The shop manuals show the belt length as 46.50" O.S.
I'm not sure what Chrysler meant by O.S. maybe Overall Size ?