1 files changed, 92 insertions, 0 deletions
diff --git a/src/ansiblelint/rules/yaml.md b/src/ansiblelint/rules/yaml.md
new file mode 100644
index 0000000..03055d0
--- /dev/null
+++ b/src/ansiblelint/rules/yaml.md
@@ -0,0 +1,92 @@
+# yaml
+
+This rule checks YAML syntax and is an implementation of `yamllint`.
+
+You can disable YAML syntax violations by adding `yaml` to the `skip_list` in
+your Ansible-lint configuration as follows:
+
+```yaml
+skip_list:
+  - yaml
+```
+
+For more fine-grained control, disable violations for specific rules using tag
+identifiers in the `yaml[yamllint_rule]` format as follows:
+
+```yaml
+skip_list:
+  - yaml[trailing-spaces]
+  - yaml[indentation]
+```
+
+If you want Ansible-lint to report YAML syntax violations as warnings, and not
+fatal errors, add tag identifiers to the `warn_list` in your configuration, for
+example:
+
+```yaml
+warn_list:
+  - yaml[document-start]
+```
+
+See the
+[list of yamllint rules](https://yamllint.readthedocs.io/en/stable/rules.html)
+for more information.
+
+Some of the detailed error codes that you might see are:
+
+- `yaml[brackets]` - _too few spaces inside empty brackets_, or _too many spaces
+  inside brackets_
+- `yaml[colons]` - _too many spaces before colon_, or _too many spaces after
+  colon_
+- `yaml[commas]` - _too many spaces before comma_, or _too few spaces after
+  comma_
+- `yaml[comments-indentation]` - _Comment not indented like content_
+- `yaml[comments]` - _Too few spaces before comment_, or _Missing starting space
+  in comment_
+- `yaml[document-start]` - _missing document start "---"_ or _found forbidden
+  document start "---"_
+- `yaml[empty-lines]` - _too many blank lines (...> ...)_
+- `yaml[indentation]` - _Wrong indentation: expected ... but found ..._
+- `yaml[key-duplicates]` - _Duplication of key "..." in mapping_
+- `yaml[new-line-at-end-of-file]` - _No new line character at the end of file_
+- `yaml[octal-values]`: forbidden implicit or explicit [octal](#octals) value
+- `yaml[syntax]` - YAML syntax is broken
+- `yaml[trailing-spaces]` - Spaces are found at the end of lines
+- `yaml[truthy]` - _Truthy value should be one of ..._
+
+## Octals
+
+As [YAML specification] regarding octal values changed at least 3 times in
+[1.1], [1.2.0] and [1.2.2] we now require users to always add quotes around
+octal values, so the YAML loaders will all load them as strings, providing a
+consistent behavior. This is also safer as JSON does not support octal values
+either.
+
+By default, yamllint does not check for octals but our custom default ruleset
+for it does check these. If for some reason, you do not want to follow our
+defaults, you can create a `.yamllint` file in your project and this will take
+precedence over our defaults.
+
+## Problematic code
+
+```yaml
+# Missing YAML document start.
+foo: 0777 # <-- yaml[octal-values]
+foo2: 0o777 # <-- yaml[octal-values]
+foo2: ... # <-- yaml[key-duplicates]
+bar: ...       # <-- yaml[comments-indentation]
+```
+
+## Correct code
+
+```yaml
+---
+foo: "0777" # <-- Explicitly quoting octal is less risky.
+foo2: "0o777" # <-- Explicitly quoting octal is less risky.
+bar: ... # Correct comment indentation.
+```
+
+[1.1]: https://yaml.org/spec/1.1/
+[1.2.0]: https://yaml.org/spec/1.2.0/
+[1.2.2]: https://yaml.org/spec/1.2.2/
+[yaml specification]: https://yaml.org/