Collections & Records in Application Design
Package of generic, common types and subtypes, many of which are generic collections and an empty instance of each.
Global, generic collections of number, string, date, etc.
Utilities for collections: parsing delimited lists and returning collections; iterating collections and returning delimited lists, boolean COUNT check function, etc.
Most of the packages I share with you here are fairly new. You are more than welcome to find errors and let me know about them (preferrably with your suggested solution).

If you need fast and random, bi-directional or multiple-pass access over a static set of data, either for lookups or comparisons, you can’t beat a collection.

If yours is a shop that builds multiple applications in a single schema or instance, it is now time to build more specific packages for storing types.  For each subsystem, you will want another package specification dedicated to defining a number of subtypes, record types and collections of record based on the columns and tables in the subsystem.  I think of this as the end of the database design phase.  Now you can move on to the detailed design of your application’s isolation layers, using your packaged types for most of the interfaces.