When a knowledge article is created from a note within an incident (or RFI), or when an existing knowledge article is applied to an incident using the Apply button next to an article in the Service Hierarchy Browser, that knowledge article is then “permanently” related to that incident. Its subject is displayed under the subject of the request.
In reality, that relation is not necessarily permanent. Because, if it turns out that the knowledge article did not resolve the issue of the requester, the request may be reopened and another knowledge article may be applied to the request. In this way, it is guaranteed that the knowledge article that finally resolved the issue is the one that is related to the incident.
There are disadvantages to this approach, however. First, the history of applied knowledge articles is not kept. Second, it could be the case that multiple knowledge article have contributed to the resolution of an incident. For these reasons, Knowledge Centered Service (KCS) prescribes that for each incident all related knowledge articles should be stored and visible. Going forward, when multiple articles have been applied to a request, all of them are displayed. This gives a much completer overview of the history of solving an incident or RFI.
Now that all knowledge articles are stored for each request, knowledge articles that were applied mistakenly are no longer overwritten. For this reason, it is now possible for a specialist to remove such an article from a request, by unrelating it from the request in Edit mode.
Note that knowledge articles that were deliberately applied to an incident or RFI but which did not immediately resolve the issue should not be unrelated. KCS prescribes to keep this data, as it can be important information for analyzing the effectiveness of knowledge articles and the teams that apply them.