ADL has defined a set of nine standard search buckets. The syntax and semantics are defined by the DTD ADL-query.dtd. When setting up your ADL collection, you must provide mappings between the search buckets and your own specific metadata. The ADL search buckets are listed below.

Geographic locations

Internal name		adl:geographic-locations
Type		spatial
Operators		contains, is-contained-in, overlaps
Content		The item's spatial footprint, i.e., an approximation of the subset of the Earth's surface to which the item is relevant, expressed as any of several types of geometric regions defined in WGS84 latitude/longitude coordinates. Learn more.

Dates

Internal name		adl:dates
Type		temporal
Operators		contains, is-contained-in, overlaps
Content		The item's temporal footprint, i.e., the range of calendar dates to which the item is relevant. Learn more.

Types

Internal name		adl:types
Type		hierarchical
Operators		is-a
Content		Terms drawn from the ADL Object Type Thesaurus identifying the meaning or content of the item. Learn more.

Formats

Internal name		adl:formats
Type		hierarchical
Operators		is-a
Content		Terms drawn from the ADL Object Format Thesaurus identifying the form or representation of the item. Learn more.

Titles

Internal name		adl:titles
Type		textual
Operators		contains-all-words, contains-any-words, contains-phrase
Content		The item's title. This bucket is a subset of the "Subject-related text" bucket. Learn more.

Originators

Internal name		adl:originators
Type		textual
Operators		contains-all-words, contains-any-words, contains-phrase
Content		Names of entities related to the origination of the item (authors, publishers, distributors, etc.). Learn more.

Assigned terms

Internal name		adl:assigned-terms
Type		textual
Operators		contains-all-words, contains-any-words, contains-phrase
Content		Subject-related terms from controlled vocabularies. This bucket is a subset of the "Subject-related text" bucket. Learn more.

Subject-related text

Internal name		adl:subject-related-text
Type		textual
Operators		contains-all-words, contains-any-words, contains-phrase
Content		Text indicative of the subject of the item, not necessarily from controlled vocabularies. This bucket is a superset of the "Titles" and "Assigned terms" buckets. Learn more.

Identifiers

Internal name		adl:identifiers
Type		identification
Operators		matches
Content		Item names and codes that serve as unique identifiers. Learn more