Use this rule to forbid non-explicitly typed truthy values other than true and false, for example YES, False and off.

This can be useful to prevent surprises from YAML parsers transforming [yes, FALSE, Off] into [true, false, false] or {y: 1, yes: 2, on: 3, true: 4, True: 5} into {y: 1, true: 5}.

Examples

When enabled the following code snippet would PASS:

    boolean: true

    object: {"True": 1, 1: "True"}

    "yes":  1
    "on":   2
    "True": 3

    explicit:
      string1: !!str True
      string2: !!str yes
      string3: !!str off
      encoded: !!binary |
                 True
                 OFF
                 pad==  # this decodes as 'N\xbb\x9e8Qii'
    boolean1: !!bool true
    boolean2: !!bool "false"
    boolean3: !!bool FALSE
    boolean4: !!bool True
    boolean5: !!bool off
    boolean6: !!bool NO

the following code snippets would FAIL:

    object: {True: 1, 1: True}

    yes:  1
    on:   2
    True: 3