# `<topicref>`

The `<topicref>` element identifies a topic (such as a concept, task, or reference) or other resource. A `<topicref>` can contain other `<topicref>` elements, allowing you to express navigation or table-of-contents hierarchies, as well as implying relationships between a containing (parent) `<topicref>` and its children. You can set the collection type of a parent `<topicref>` to determine how its children are related to each other. You can also express relationships among `<topicref>` elements by using group and table structures (such as `<topicgroup>` and `<reltable>`). Relationships are expressed as links in the output; by default, each participant in a relationship has links to the other participants in that relationship.

Category: Basic map elements