Citations are an important element of any metadata record as they are the mechanism used to refer to other things. The ISO Citation offers a considerable improvement over the FGDC Citation.
FGDC: The FGDC Citation is built using the Scientific Publication Model. The Citation does not include contact information because that information is included in the paper. The On-Line Linkage is free text, so it has no structure. This reflects the poorly developed nature of the web at the time that the FGDC was developed. No one understood how the web was going to be used. Finally, the Larger Work Citation offers a weak aggregation approach. There are not many options for describing the relationships between items.
<i>FGDC Citation:</i> + originator [1..*] : CharacterString + publication date : Date + publication time [0..1] : Time + title : CharacterString + edition [0..1] : CharacterString + geospatial data presentation form [0..1] : CharacterString + series information [0..1] : name, issue identification + publisher information [0..1] : publication place, publisher + other citation details [0..1] : CharacterString + online linkage [0..*] : URL + larger work citation [0..1] : Citation
ISO: On the surface, the ISO citation is very similar to the FGDC Citation. Many of the fields are essentially the same. The ISO Citation requires only a title and a date. The originator is not required. In fact, neither the Originator or the Publisher show up directly in the ISO Citation. These show up in the very powerful ISO object CI_ResponsibleParty described below. Note that the citation can include any number of responsible parties.
<i>ISO Citation</i> + title : CharacterString + alternateTitle [0..*] : CharacterString + date [1..*] : CI_Date + edition [0..1] : CharacterString + editionDate [0..1] : Date + identifier [0..*] : MD_Identifier + citedResponsibleParty [0..*] : CI_ResponsibleParty + presentationForm [0..*] : CI_PresentationFormCode + series [0..1] : CI_Series + otherCitationDetails [0..1] : CharacterString + collectiveTitle [0..1] : CharacterString + ISBN [0..1] : CharacterString + ISSN [0..1] : CharacterString