Basic Rules of YAML - YAML tutorial

There are only three very simple rules to remember when writing YAML files.

INDENTATION: YAML does not allow the use of tabs. Spaces are used instead of tabs because tabs are not universally supported.

COLONS: Dictionary keys are represented in YAML as strings terminated by a trailing colon. Values are represented by either a string following the colon, separated by a space:

key: value

DASHES:  To represent lists of items, a single dash followed by a space is used. Multiple items are a part of the same list as a function of their having the same level of indentation.

- list_value_one- list_value_two- list_value_three

Note: YAML is case sensitive.