This is implemented as the front matter attribute "draft". If you are using the legacy front matter, you write it as:
If you write it using the Awestruct integration with AsciiDoc headers, then you write it as:
= Title of Post
Anytime you are setting an Awestruct-specific front-matter variable in an AsciiDoc document, you need to prefix it with awestruct- for it to be recognized. I'm thinking about making this more generic, but for now, that's how it's done.
Unfortunately, when you do this, it excludes the draft post even in development mode. I noticed in the Jekyll docs that Jekyll provides a switch to turn on rendering of drafts . I think it's reasonable to enable them in development mode by default and use a site config variable to override this behavior in any profile. I'll file an issue.