Dictionary (Flat Vocabulary)

Definition, description, and example of a dictionary

Flat Vocabularies Multi -Level Vocabularies Relational Vocabularies
Authority File Glossary Dictionary Gazetteer Code List Taxonomy Subject Heading Thesaurus Semantic Network Ontology

Definition of Dictionary

In the context of metadata, a dictionary is a type of controlled, flat vocabulary that provides a list of metadata terms, definitions, and additional information within a specific domain.


In practice, a dictionary builds upon a glossary by providing additional information about each term, or value. This additional information might include how the value came to be selected, the etymology of the value, or additional, site-specific context for each value. A dictionary provides more than a definition, but the nature of the additional information is subject to each project’s interpretations.

Example - CDI Sea Search (SeaDataNet) Vocabularies

  • "USPC","Unspec.","Not specified","Use for parameters where the units are deliberately undefined such as arbitrary units","2/2/05 16:14",""
  • "UKWN","Unknown","Not known","Use for parameters that should have a unit, but it is not known. Usage of this code is STRONGLY DISCOURAGED","2/2/05 16:16",""
  • "UPPM","ppm","Parts per million","Usage not recommended for parts per million by weight. Use milligrams/kilogram instead.","16/9/1994 00:00:00","18/10/1995 13:36:11"
  • "UAQU","A^2/Q","Angstrom squared per quanta","Scaled unit by Avagadro's number and powers of ten to m**2/mol","2/2/05 16:49",""
  • "USVD","Sv","Sverdrup","One Sverdrup is a million cubic metres per second or a million cumecs","17/2/2005 12:44:16","14/10/2005 11:47:50"
  • "UNPI","ng","Nanograms","Changed from nanograms per individual when per individual semantics transferred to the parameter description","10/2/00 0:00","3/8/05 8:52"
  • "UAAA","deg","Degrees","","1/1/87 0:00","4/11/05 12:47"
  • "UABB","deg T","Degrees True","","1/1/87 0:00","4/11/05 12:47"

This dictionary provides a code, a short title, a full title, comments, creation date, and modification date, in csv format. It clearly tells us about the management of this vocabulary, which is very useful for selecting a vocabulary.

Suggested Citation

Neiswender, C. 2011. "Dictionary (Flat Vocabulary)." In The MMI Guides: Navigating the World of Marine Metadata. http://marinemetadata.org/guides/vocabs/voctypes/voccat/dictionary. Accessed September 26, 2020.