How to Group Related Links by Type

By default, all links from DITA relationship tables or related link elements within topics are grouped under one "Related information" heading:

Related information
  Target Topic
  Target Concept
  Target Task

It is possible to group the links by target type (topic type) by setting the webhelp.rellinks.group.mode=group-by-type parameter. The output will look like this:

Related concepts
  Target Concept
Related tasks
  Target Task
Related information
  Target Topic