Explanation, or discussions, clarify and illuminate a particular topic. They broaden the documentation’s coverage of a topic.
They are understanding-oriented.
Explanations can equally well be described as discussions; they are discursive in nature. They are a chance for the documentation to relax and step back from the software, taking a wider view, illuminating it from a higher level or even from different perspectives. You might imagine a discussion document being read at leisure, rather than over the code.
This section of documentation is rarely explicitly created, and instead, snippets of explanation are scattered amongst other sections. Sometimes, the section exists, but has a name such as Background or Other notes or Key topics - these names are not always useful.
Discussions are less easy to create than it might seem - things that are straightforward to explain when you have the starting-point of someone’s question are less easy when you have a blank page and have to write down something about it.
A topic isn’t defined by a specific task you want to achieve, like a how-to guide, or what you want the user to learn, like a tutorial. It’s not defined by a piece of the machinery, like reference material. It’s defined by what you think is a reasonable area to try to cover at one time, so the division of topics for discussion can sometimes be a little arbitrary.
Explanations are the place for background and context - for example, SNMP requests and how they are handled in NOC.
They can also explain why things are so - design decisions, historical reasons, technical constraints.
Discuss alternatives and opinions¶
Explanation can consider alternatives, or multiple different approaches to the same question. For example, in an article on Django deployment, it would be appropriate to consider and evaluate different web server options,
Discussions can even consider and weigh up contrary opinions - for example, whether test modules should be in a package directory, or not.
Don’t instruct, or provide technical reference¶
Explanation should do things that the other parts of the documentation do not. It’s not the place of an explanation to instruct the user in how to do something. Nor should it provide technical description. These functions of documentation are already taken care of in other sections.