New Rule: Separator Line Length

[nithinbandaru1]

New Rules

Rule	Type	Default	Description
MD035.length	int	3	Expected number of characters used in the separator line
MD035.character	char	-	Character used for the separator (-, *, _)

Why this is useful

• Ensures consistent visual structure across markdown files
• Reduces noise in code reviews due to stylistic differences
• Helps teams enforce documentation standards
• Aligns with how other linting rules enforce structural consistency

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Updates to question

• Removed
  • | separator_line_allow_spaces | boolean | false | Whether spaces between separator characters are allowed (e.g., - - -) |
• Updated to fit with existing rule MD035.

[DavidAnson]

If you want to enforce a specific horizontal rule style, you can do that already with rule MD035: https://github.com/DavidAnson/markdownlint/blob/main/doc/md035.md

[nithinbandaru1]

Thanks for pointing this out @DavidAnson.
I’ve updated the proposal to extend the existing MD035 rule instead of introducing a separate rule.

[DavidAnson]

Why does the rule merit any changes? If there is a specific syntax you prefer for horizontal rules, you can specify it directly.

[hfrmobile]

Is it possible to configure that separator lines must not be used (= reports it if used, regardless which characters)?