The user enters a Markdown document in an outline.

How to interpret indentation?

This is a design puzzle for content management.

To solve the puzzle you need to have a design-level understanding of three things:

In the first approach we ignore indentation.

As we generate Markdown text from the outline, we go into sub-heads, but we don't indent with tabs, add any Markdown syntax, or HTML syntax.

Consider this example:

What we would generate, in Markdown, is this:

This is the approach I take in the software I'm working on, but have not released. It's the most conservative approach. It says outline indentation is a writing aid, but has no effect on the rendering. It may be possible to add interpretation for structure in the future, but if we do it we would break existing users.

Note: This approach is pure fiction. I don't think it's possible in Markdown.

Having used an outline-based CMS for many years, the approach I like best is the one that you're reading right now. The structure is reflected in an HTML outline with wedges that can be used to collapse or re-expand the text.

This way I can organize my writing and have that organization reflected in the readers' experience.

So in the example we're using the to-do list would look like this:

Use Markdown syntax to indicate list structure.

We might render the list as follows:

However, unless I'm missing something, Markdown sees one flat list, not a list with a second item containing its own sub-list with two items. In other words, there's no concept of nested lists in Markdown?

Or we might render it thus, to give emphasis to the main head:

This approach is needed to help the eye pick up the structure when looking at a long list, each with a lot of subs.

I wanted to put this out for comment, because I want to make the best use of outlining and Markdown, and my experience with Markdown is very limited.