Project:Properties

See also: Project:About

lgbtDB's properties (P-identifiers, or PIDs) serve as the predicates in its structured data model, defining what kind of relation or attribute links an item to a value, qualifier, or reference. They are analogous to properties on Wikidata (or any other Wikibase instance) but are scoped and maintained more specifically to the LGBTQIA+ domain.

Introduction

Properties

In knowledge graphs and semantic databases, properties define relationships between entities or between an entity and a literal value. A property acts as the predicate in a subject-predicate-object triple, specifying what kind of precise connection exists. Properties are central to structured data because they establish meaning, enabling logical inference, linking, and rich querying across datasets. Each property has a defined scope, datatype, and intended domain (the types of things it applies to) and range (the kinds of values it can take).

Properties in RDF

In the Resource Description Framework (RDF), properties are defined as IRIs that represent predicates in RDF triples. Every RDF statement is built in the triple form subject-predicate-object. Here, the predicate is the property connecting the subject and object. RDF treats all properties as instances of the class rdf:Property, and these may be used without predefined typing, although vocabularies often subclass them for specific roles.

Properties in OWL

In the Web Ontology Language (OWL), properties are enriched with formal semantics. OWL distinguishes between different types of properties based on what they link, being annotation properties, data properties, or object properties. OWL also enables expressing property characteristics, such as symmetry, transitivity, functionality, or inverse relations.

Annotation properties

Annotation properties in OWL are used for metadata rather than logical assertions. They provide human-readable or organizational context for classes, properties, or individuals. Common annotation properties include:

• rdfs:label: provides a human-readable name
• rdfs:comment: provides a textual description
• dc:source, dc:creator, or prov:wasDerivedFrom: representing provenance or authorship information

These do not affect reasoning or entailments, but they are vital for documentation, interoperability, and multilingual support.

Data properties

Data properties link entities (individuals) to literal values such as strings, numbers, or dates. In RDF, these are predicates whose range is a datatype (e.g. xsd:string, xsd:dateTime, xsd:boolean). In OWL, data properties can have constraints (domains, ranges, cardinality) and can be used in reasoning (e.g., restricting a class to individuals with a particular data value).

Properties in Wikibase

In a Wikibase instance, properties play a similar role to those in RDF and OWL but are represented and stored within a structured data model designed for collaborative editing. Each Wikibase property (identified by a unique PID such as "P42") defines a relationship or attribute that can appear in statements on items. Statements consist of:

• a subject (an item, e.g., "Q1234")
• a property (e.g., "P31")
• a value (an item, literal, or other datatype)

In the RDF export format, Wikibase represents properties as both entities (metadata about the property itself) and predicates (usable in triples). Property entities are represented at IRIs like wbt:P31. Their predicates in RDF export appear as wdt:P31, p:P31, ps:P31, pq:P31, etc., each with a specific meaning:

• wdt:P31, being the direct claim (simplified RDF form).
• p:P31, being the full statement node.
• ps:P31, being the main snak (the actual value).
• pq:P31, being the qualifier.

This differs from generic RDF/OWL properties in that Wikibase introduces these layered IRIs to represent statement structure (allowing qualifiers, references, and ranks), which RDF/OWL do not natively support. More documentation regarding the representation of properties in the RDF dump format can be found here.

Property data types

Each property on lgbtDB has a datatype (e.g., Item, String, URL, Monolingual text, Quantity, Time, etc.) and may carry constraints, descriptions, aliases, and mapping links to external vocabularies or databases (such as Wikidata).

Commons media file

The Commons media file datatype stores filenames of files on Wikimedia Commons (e.g., images, videos). This datatype is used to associate visual or media content with items. For an example on lgbtDB, see photo (P398).

EntitySchema

The EntitySchema datatype links to an EntitySchema (a Shape Expressions or ShEx schema used to describe data patterns in Wikibase). This enables validation and modeling. Currently, entity schemas are not used on lgbtDB.

External identifier

An External identifier holds external IDs that identify the same entity in another system (e.g., VIAF, IMDb, or Wikidata IDs).

Geographic shape

A Geographic shape represents a geoshape stored on Wikimedia Commons (usually a .map or .geojson file). These files are used for geospatial visualization.

Constraints

See also: Project:Property Constraints

Properties By Subject

External Identifiers

Biomedical Identifiers

A number of biomedical identifiers are utilized on lgbtDB. This is in part due to the historical and contemporary pathologization and medicalization of LGBTQIA+ peoples, as well as due to the ways LGBTQIA+ people interact with medical systems.

Many identifiers are species-specific, which is preserved on lgbtDB. For example, FMAIDs (Foundational Model of Anatomy IDs) only appear on entities where there is "part of taxon" human and UBERON IDs do not.

List of Properties

A full list of properties, which can be modified to list only properties of a given type, can be found here.

Sorting of Properties

See also: MediaWiki:Wikibase-SortedProperties

The order of properties is specified in this page here.