guideline

Record structures should not always be flat. Factor out common parts.

For a large record structure, group related components into smaller subrecords.

For nested records, pick element names that read well when inner elements are referenced.

Consider using type extension to organize large data structures.

type Coordinate is
   record
      Row    : Local_Float;
      Column : Local_Float;
   end record;
type Window is
   record
      Top_Left     : Coordinate;
      Bottom_Right : Coordinate;
   end record;

rationale

You can make complex data structures understandable and comprehensible by composing them of familiar building blocks. This technique works especially well for large record types with parts that fall into natural groupings. The components factored into separately declared records, based on a common quality or purpose, correspond to a lower level of abstraction than that represented by the larger record.