Topics are tags that are added to Salesforce Knowledge Articles to provide better relevance for specific keywords.
More on Topics for articles: https://developer.salesforce.com/docs/atlas.en-us.knowledge_dev.meta/knowledge_dev/sforce_api_objects_topicassignment.htm
They are not actually a part of the article. Much like Data Categories, they are related objects. You also don't need to edit an article to add a Topic, which makes it easy for authors to use.
We'd like to enable Topics on Articles in our org, but would only like to do so if Coveo can index them.
Here is another dev resource related to Salesforce Topics: https://releasenotes.docs.salesforce.com/en-us/winter14/release-notes/rn_186_knowledge_topics.htm
Answer by maveilleux · Nov 14, 2016 at 08:44 AM
Yes, we can index them. If you are on-prem, simply add the child relationship `Select Topic.Name from TopicAssignments' in your ObjectsToGet on the KAV object. If cloud, contact support, they will be able to add it.