What is the difference between “Simple” (“unqualified”) and “Qualified” Dublin Core?
“Simple Dublin Core” is Dublin Core metadata that uses no qualifiers; only the main 15 elements of the Dublin Core Metadata Element Set are expressed as simple attribute-value pairs without any “qualifiers” (such as encoding schemes, enumerated lists of values, or other processing clues) to provide more detailed information about a resource. “Qualified Dublin Core” employs additional qualifiers to further refine the meaning of a resource. One use for such qualifiers are to indicate if a metadata value is a compound or structured value, rather than just a string. Qualifiers allow applications to increase the specificity or precision of the metadata. They may also introduce complexity that could impair the metadata’s compatibility with other Dublin Core software applications. With this in mind, designers should only select from the set of approved Dublin Core qualifiers that were developed by the Dublin Core community process. Unfortunately, qualifiers often introduce additional complexi
