A Package Import relationship is drawn from a source Package to a Package whose contents are to be imported. Private members of a target Package cannot be imported. The relationship is typically used in a Package diagram.
OMG UML Specification
The OMG UML specification (UML Superstructure Specification, v2.0, p. 38) states:
"A package import is a relationship between an importing namespace and a package, indicating that the importing namespace adds the names of the members of the package to its own namespace. Conceptually, a package import is equivalent to having an element import to each individual member of the imported namespace, unless there is already a separately-defined element import."