Objects are components of a publication. For example, a Notice to Mariners publication contains chart notices with instructions. The publication can also include temporary or preliminary notices also with instructions.
All the Notice to Mariner components: publication, chart notices, temporary or preliminary notices, and instructions are stored as objects in the catalogue.
Read-only base objects provide building blocks for other objects in a catalogue.
For example, the base object, NTC_BASE_PERM_CHART_NOTICE contains basic attributes that define notices. You can extend the base notice with your own notice object suitable to your publication. In this case, NTC_CHART is derived from NTC_BASE_PERM_CHART_NOTICE
SURVEY_INFO is custom object with no base object. In this case, a section named Additional Information is part of this publication. SURVEY_INFO contains attributes that define Additional Information. Custom objects provide versatility to define non-standard sections of a publication.
A Unified Modelling Language (UML) representation of the HPD Publication Catalogue base objects and related objects in the sample catalogue is available in UML Diagram of the Publications Catalogue.