Rule - MD035#

Property	Value
Aliases	`md035`, `hr-style`
Autofix Available	Yes
Enabled By Default	Yes

Summary#

Enforce a consistent style for horizontal rules.

Reasoning#

Readability#

Horizontal rules visually separate content sections. Using a consistent style (such as ---, ***, or ___) improves document uniformity and makes it easier for readers to scan and distinguish structural breaks from other content.

Examples#

Failure Scenarios#

This rule triggers when the horizontal rule marker style is not consistent throughout the document. With the default configuration, the first marker sets the style used throughout the document.

---

-  -  -

***

***********

Explanation: The first horizontal rule uses ---, establishing --- as the expected style. The subsequent rules use - - - (dashed with extra spacing), *** (asterisk style), and *********** (longer asterisk run), none of which match the established --- style, causing violations.

Unlike the previous example, this scenario uses a configured style (* * *) that the second marker does not match.

* * *

---

Explanation: The configuration explicitly requires the style set to * * *. The first marker matches this style. The second marker --- does not match the configured style * * *, causing a violation.

Unlike the previous examples, this scenario demonstrates a mismatch between dash and underscore horizontal rule styles.

---

___

Explanation: The first horizontal rule uses ---, establishing --- as the expected style (under the default consistent configuration). The second rule uses ___, which is a valid horizontal rule marker but does not match the established dash style, causing a violation.

Unlike the previous examples, this scenario demonstrates a mismatch caused by inconsistent spacing within the same character type.

***

* * *

Explanation: The first horizontal rule uses *** (no spaces), establishing *** as the expected style. The second rule uses * * * (with spaces), which is a valid horizontal rule marker but does not match the established no-space style, causing a violation.

Correct Scenarios#

This rule does not trigger when every horizontal rule marker is the same throughout the document.

---

---

Explanation: Both horizontal rules use the --- style. Since the style is consistent throughout the document, no violations occur.

Unlike the previous example, this scenario includes leading whitespace before the markers.

---

  ---

Explanation: Indentation is not part of the horizontal-rule style; only the marker characters define the style. Both markers are ---, so the document remains stylistically consistent and the rule does not trigger.

Unlike the previous examples, this scenario demonstrates consistent use of the underscore horizontal rule style.

___

___

Explanation: Both horizontal rules use the ___ style. Since the style is consistent throughout the document, no violations occur. This confirms that any consistent style (not just ---) is acceptable.

Unlike the previous examples, this scenario includes a two-character sequence (--) that is too short to be a valid horizontal rule.

--

Explanation: A horizontal rule requires three or more consecutive delimiter characters (-, _, or *). The sequence -- has only two characters and therefore is not recognized as a horizontal rule at all. Since no horizontal rule is present, the rule has nothing to compare and does not trigger.

Fix Description#

All horizontal rules are replaced with the configured thematic break text. If the configuration is the default consistent, the first horizontal rule establishes the style text used throughout the document.

Configuration#

Prefixes
`plugins.md035.`
`plugins.hr-style.`

Value Name	Type	Default	Description
`enabled`	`boolean`	`True`	Whether the Rule Plugin is enabled.
`style`	`string`	`consistent`	`consistent` for consistent style, or a specific marker (three or more `-`, `_`, or `*` characters with optional whitespace; cannot start or end with a space)

Origination of Rule#

This rule is largely inspired by the MarkdownLint rule MD035.