Chapter-one sample: define the object
Record boundaries
For an article catalogue, one record represents an article. For physical lending, distinguish a title from a particular copy. Define the object before choosing fields to avoid mixing levels.
Field responsibilities
Identifiers identify, subjects aid discovery and sources support review. Putting status in a name makes an object hard to recognize after updates; give status its own field.
Exercise
Define one record for a technical-document collection, then specify identifiers, subjects and sources, including a checking rule for each.