🔢rdf:Seq

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Also known as: RDF Sequence

RDF container class representing an ordered collection via numbered membership properties.

DESCRIPTION

rdf:Seq is an RDF container for ordered collections whose items are linked by container membership properties (rdf:_1, rdf:_2, …). It provides order but lacks deterministic semantics across serializations compared to rdf:List. Modern practice prefers rdf:List or domain-specific constructs for consistency and tooling support.

ALTERNATIVE DEFINITIONS

W3C RDF Schema 1.1

RDF defines three container types: Bag, Seq, and Alt. A Seq is used to indicate membership in a sequence where order is significant.

Identifies Seq as the ordered RDF container.

Source

Wikipedia

A Seq is an ordered collection; items are associated with the container via properties named rdf:_1, rdf:_2, etc.

Highlights ordered membership via numbered predicates.

Source

RELATED TERMS

RDF RDF Schema RDF Container rdf:Bag rdf:Alt SPARQL Turtle OWL

COMPETING TERMS

rdf:List

KNOWLEDGE AREAS

Semantic & Knowledge Modeling Data Modeling Data Integration & Interoperability

TARGET AUDIENCE

Data Modeler Data Architect Data Engineer Information Analyst Data Steward

EXTERNAL SOURCES

• Wikipedia - RDF Schema
• W3C - Official RDF container definition
• Apache Jena - Working with RDF Seq
• W3C - Primer describing containers

TOP QUESTIONS

What is rdf:Seq and why is it used?

rdf:Seq is the RDF container for ordered collections. It encodes position using rdf:_n predicates and is used when order matters but lists are not employed.

Category: Definition

How does rdf:Seq compare to rdf:List?

rdf:Seq uses numbered predicates and is less deterministic across serializations than rdf:List. Lists are more widely supported and recommended in modern RDF.

Category: Comparison

How can I query the items of an rdf:Seq?

Use SPARQL patterns matching rdf:_1, rdf:_2, etc., or property path expressions. Remember that positions are implicit in predicate names.

Category: HowTo

Are RDF containers like rdf:Seq considered outdated?

They are legacy. Prefer rdf:List or domain vocabularies unless compatibility needs dictate container use.

Category: Opinion

What are common pitfalls with rdf:Seq?

Missing or misnumbered rdf:_n properties can corrupt order. Mixing containers with lists may confuse consumers.

Category: Mistakes

Does rdf:Seq support duplicate elements?

Yes. Containers represent membership, not set uniqueness, so duplicates are allowed.

Category: Capabilities

Is rdf:Seq suitable for large sequences?

Large sequences can be hard to maintain due to manual numbering. rdf:List offers more consistent traversal.

Category: Risks

How is rdf:Seq serialized in Turtle?

Turtle has no special syntax for containers; positions are expressed via rdf:_n predicates on the container node.

Category: Syntax

Can rdf:Seq be nested?

Yes, sequences can contain other containers or lists. Ensure consumers can handle nested memberships.

Category: Capabilities