DITA provides support for various types of linking between topics, some of which is automated, while some is specified by the author. Oxygen XML Editor provides support for all forms of linking in DITA.
A DITA map creates a hierarchical relationship between topics. That relationship map expresses a narrative flow from one topic to another, or it may be used as a classification system to help the reader find topics based on their classification, without creating a narrative flow. Because the relationship between topics in a hierarchy can be different in this way, you may want to create links between topics in various different ways. For instance, if your topics are supposed to be organized into a narrative flow, you may want to have links to the next and previous topics in that flow. If your topics are part of a hierarchical classification, you may want links from parent to child topics, and vice versa, but not next and previous links.
Parent, child, and sibling links are created automatically by the DITA output transformations (and may differ between various output formats). The kinds of links that are created are determined by the DITA collection-type attribute, which you can set in the DITA Maps Manager by selecting a topic and Edit properties... from the contextual menu.
In addition to the relationships between topics that expressed by their place in the hierarchy of a map, a topic may be related to other topics in various ways. For instance, a task topic may be related to a concept topic that gives the background of the task, or to a reference topic that provides data needed to complete the task. Task topics may also be related to other tasks in a related area, or concepts to related concepts.
Typically, they are grouped in a list at the end of the topic, though this depends on the behavior of the output transformation. DITA provides two mechanisms for expressing relationships between topics at the topic level: the related-links section of a topic, and relationship tables in maps.
Oxygen XML Editor provides tools for inserting related-links and relationship tables.
DITA supports linking within the text of a topic using the xref element. The destination of the link can be expressed directly using the href attribute or indirectly using the keyref attribute. If you use the keyref attribute, you link to a key rather than directly to a topic. That key is then assigned to a topic in a map that includes that topic. This means that you can change the destination that a key points to either by profiling the key definition in the map or by substituting a different map in the build.
Oxygen XML Editor provides support for creating both direct links and key links, assigning keys to topics in a map, and profiling maps.
Links can break for a number of reasons. The topic that a link points to may be renamed or removed. A topic may be used in a map that does not include a topic it links to. A topic or a key may not exist in a map when a particular profile is applied. The DITA Maps Manager provides a way to validate all the links in the document, or documents described by a map. This can include checking with each of a set of profiling conditions applied.