Page History

...

With DSpace you can describe digital objects such as text files, audio, video or data to facility facilitate easy retrieval and high quality search results. These descriptions are organized into metadata fields that each have a specific designation, for example .  For example:  dc.title stores the title of an object, while dc.subject is reserved for subject keywords.

For many of these fields, including title and abstract, free text entry is the de facto proper choice, as the values are likely to be unique. Other fields are likely to be associated with values that can occur across different itemshave values drawn from controlled sets. Such fields include unique names, subject keywords, document types and other classifications. For those kinds of fields the overall quality of the repository metadata increases if values with the same meaning are normalized across all items. Additional benefits can be gained if unique identifiers are associated as well in addition to canonical text values associated with a particular metadata field.

...

The value pairs system works great well for short and flat lists of choices. DSpace offers a second way of structuring and managing more complex, hierarchical controlled vocabularies. In contrast to the value pairs system, these controlled vocabularies are managed in separate XML files in the [dspace]/config/controlled-vocabularies/ directory instead of being entered straight into input-forms.xml

...