A commutative ring with
identity is compactly packed by primes (briefly: a C. P.-ring) if whenever an ideal I of
R is contained in the union of a family of prime ideals of R, then I is actually
contained in one of the primes of the family. The aim of this note is to characterize
Noetherian P. C.-rings ideal theoretically and, with suitable restrictions, in terms of
Picard groups.