There are three types of AsciiDoc documents: article, book and manpage. All document types share the same AsciiDoc format with some minor variations. If you are familiar with DocBook you will have noticed that AsciiDoc document types correspond to the same-named DocBook document types.

Use the asciidoc(1) -d (--doctype) option to specify the AsciiDoc document type — the default document type is article.

By convention the .txt file extension is used for AsciiDoc document source files.