YARD is a documentation generation tool for the Ruby programming language. It enables the user to generate consistent, usable documentation that can be exported to a number of formats very easily, and also supports extending for custom Ruby constructs such as custom class level definitions. What's this mean? It means YARD is a great tool to document applications that make use of DSLs. http://yardoc.org/docs/yard/file:docs/GettingStarted.md
From the document, and the defined annotations are very useful for code completion and navigation.
# Converts the object into textual markup given a specific format.
# @param [Symbol] format the format type, `:text` or `:html`
# @return [String] the object converted into the expected format.
def to_format(format = :html)
# format the object