if anyone knee what the R-PIII on the P-2 and P-3 cards was?
These were extra coupons for items which the authorities were able to supply in larger quantities in certain months. The info about the sort of additional goods was published in newspapers.
More interesting facts here
One time in my neighborhood someone sold a stork! Claiming it was a goose.
That legend was told all over Poland. :) One time it was a stork, another a swan. :):)