In a DITA Map, you can create topic sequence type of linking when there’s an order to topics that you want to show in the related links. The sequence type of linking is used in HTML outputs and shows as next and previous links at the bottom of the topics.
Note:
In PDF outputs, the related links does not show sequencing.
Important:
Create sequences only when a definite order in which the topics should be read or performed in a specific order. Creating sequences of your entire publication is not appropriate because there’s not a real sequence to many topics, like topics in your overview or a group of administration tasks that can be performed at any time in any order. If there are related topics you’d like to point the user to, you should use regular relationship table links.
To set up sequencing, you can use the topicgroup element in a reltable row in the DITA Map. When setting up a sequence, consider the following:
If the topic order in the hierarchy matches the order that you listed within the map, you can just wrap the topics in the hierarchy with the topicgroup element instead of using the reltable. This won’t be very common.
If the sequence is different than the topic order, you can set up the topicgroup in the reltable, copy the topics into the topicgroup, and use the toc attribute to hide the duplicate topics in the TOC.
If you use the same map in a publication from where you produce a PDF, you can use the HTML condition to hide the sequence topicgroup in the PDF if you do not want the related links to appear in the PDF.
If you use the same publication to produce the PDF and HTML outputs and you want to use the HTML condition to hide the topicgroup in the PDF, you must consider creating a separate publication for the HTML. Alternatively, you need to change the conditions back and forth to produce the outputs and that introduces risk, and not recommended.
You can technically set up a topicgroup in the topic hierarchy of a DITA Map. If you do that, ensure that you apply the HTML condition to the topicgroup to exclude it from the PDF output. Otherwise, the topics will appear in the PDF twice.
Use the topic sequencing only in situations where it adds value and there’s an actual sequence to the topics.