1. A computer-readable medium having stored thereon a data structure for use in defining a database schema object comprising: a first field comprising data representing a label for a data structure, said data structure associated with and private to a parent record; a second field comprising data representing a field code for a reusable custom-defined nestable compound data type; a third field comprising data representing a type identifier naming a set of related data fields associated with said data structure, said set of related data fields further associated with at least one private sub-record; and a fourth field comprising data representing a Boolean indicator, a truth value of said Boolean indicator permissive of said data structure being associated with a plurality of private sub-records.