Comparison with Obsidian Linter¶

This page maps every Obsidian Linter rule to its rumdl counterpart, so that a vault owner can judge a migration before starting it, and so that a rule request for something rumdl lacks arrives pre-triaged.

Last verified: August 2026 against Obsidian Linter's generated rule documentation. Obsidian Linter changes over time; if a row is out of date, please open an issue.

Quick Summary¶

rumdl and Obsidian Linter are different kinds of tool that overlap on formatting:

• rumdl is a file linter and formatter. It runs as a CLI, in pre-commit, as an LSP server, in VS Code, and inside Obsidian through the obsidian-rumdl plugin, which runs the same rule engine on the notes in a vault. Its rules read only files on disk (the file, and the workspace for cross-file rules), so a run is reproducible in CI.
• Obsidian Linter is an editor plugin. Besides formatting rules it has rules that run when text is pasted, rules that read the file system (creation and modification times, the file name), and user-defined regex replacements and shell commands.

Of Obsidian Linter's 65 rules, 16 have a rumdl equivalent, 12 overlap partially (same idea, different contract), 28 have no rumdl counterpart, and 9 are out of scope by construction: the 8 paste rules and YAML timestamp. A file linter has no paste event, and a formatter that writes the current time into the file on every run cannot be idempotent, so those rows are not gaps that a rule request could close.

Of the 28 without a counterpart, 12 concern the front matter (11 write or rewrite YAML values, Compact YAML removes blank lines inside it), 3 handle spacing around CJK and fullwidth characters, and the remaining 13 are one-off transforms.

How the Two Tools Differ¶

Rule Mapping¶

Legend: Yes means an equivalent rule exists and every explicit option maps (a difference in how a consistent style is inferred is noted on the row, not demoted), Partial means the rules overlap but an option or direction has no counterpart, None means rumdl has no such rule, and Out of scope means a file linter cannot do it. Where an Obsidian Linter option has a rumdl option, the Notes column names it.

YAML Rules (14)¶

The general settings "Default escape character" and "YAML aliases section style" configure YAML value formatting and have no rumdl equivalent.

Heading Rules (5)¶

Footnote Rules (3)¶

Content Rules (16)¶

Spacing Rules (19)¶

Paste Rules (8) and Custom Rules¶

The eight paste rules (blockquote indentation on paste, double checklist and list marker prevention, proper ellipsis on paste, remove hyphens on paste, remove leading or trailing whitespace on paste, remove leftover footnotes from a quote on paste, remove multiple blank lines on paste) transform the clipboard contents at paste time. There is no paste event in a CLI, a pre-commit hook or a language server, so they are out of scope.

"Custom regex replacement" and "Custom commands" are None: rumdl has no user-defined rules.

Starter Configuration¶

This .rumdl.toml enables the Obsidian flavor and the opt-in rules that have an Obsidian Linter counterpart, and sets the options whose rumdl default differs from Obsidian Linter's. Drop the sections for rules you did not use in Obsidian Linter.

[global]
flavor = "obsidian"
# Opt-in rules with an Obsidian Linter counterpart:
# MD063 Capitalize headings, MD072 YAML key sort, MD088 Quote style
extend-enable = ["MD063", "MD072", "MD088"]

# Capitalize headings
[MD063]
style = "title-case"
preserve-cased-words = true
ignore-words = ["macOS", "iOS", "iPhone", "iPad", "JavaScript", "TypeScript", "AppleScript", "I"]

# YAML key sort: list the keys from "YAML key priority sort order"
[MD072]
key-order = ["title", "aliases", "tags"]

# Quote style (straight quotes, Obsidian Linter's default direction)
[MD088]
normalize-quotes = true

# Remove trailing punctuation in heading: add the fullwidth forms
[MD026]
punctuation = ".,;:!。，；：！"

# Remove empty lines between list markers
[MD076]
style = "tight"

# Trailing spaces: strip hard line breaks too, Obsidian Linter's default.
# Drop this section to keep 2-space hard line breaks ("Two Space Linebreak").
[MD009]
br-spaces = 0

Rules that are on by default in rumdl and have a direct counterpart (MD012, MD022, MD023, MD031, MD034, MD047, MD058, MD065, MD069, MD071, MD004, MD049, MD050) need no configuration; the differences noted on their rows are fixed behavior, not options. To keep a behavior Obsidian Linter never touched, disable the rule:

[global]
flavor = "obsidian"
disable = ["MD010"]  # keep tabs

Known Behavioral Differences¶

1. consistent follows the majority, not the first occurrence. Obsidian Linter's consistent style for emphasis, strong and unordered lists takes the first marker in the file as the standard. rumdl's MD004, MD049 and MD050 take the most prevalent marker, with a fixed tie-break (dash for lists, asterisk for emphasis). A file whose first list uses * and whose other lists use - converges to - under rumdl and to * under Obsidian Linter.
2. MD064 leaves some space runs alone on purpose. A run of 4, 8 or 12 spaces reads as a replaced tab and is skipped so that MD064 does not undo MD010 at its default width, spaces after a task checkbox are skipped, and the item lines of a list of at least two items that are all column-aligned are skipped. Obsidian Linter's "Remove multiple spaces" collapses all of these. See MD064 for the full exception list.
3. MD027 only removes spaces. > text becomes > text, but >text is not given a space. Obsidian Linter's "Blockquote style" adds it.
4. MD039 leaves wikilinks alone. [[Page| alias ]] keeps its spaces under rumdl because the pipe text of a wikilink has no destination it could be normalized against. Obsidian Linter trims it.
5. MD088 only goes toward ASCII. It replaces smart quotes with straight ones and, with normalize-dashes = true, dashes with hyphens. Obsidian Linter can also convert straight quotes to smart quotes; rumdl cannot.
6. MD040 inserts text. Obsidian Linter's "Default language for code fences" inserts the language you configure. rumdl's fix inserts text (except under the mdg flavor, where a Doc String's label is its media type and is left to the author), and the MD040 options normalize labels that are already present rather than choose a default.
7. MD001 has no "start at level 2". rumdl checks that heading levels increment by one; it has no option to shift every heading so the document starts at H2.
8. MD029 never changes the marker delimiter. 1) and 1. are both accepted and neither is converted to the other.
9. MD072 sorts every unlisted key ascending. There is no "None" or "Descending" mode for keys outside key-order, and the fix is skipped when the front matter contains a comment line, which a reorder could leave next to the wrong key. An inline comment after a value moves with its line.
10. MD026's default punctuation set is ASCII. Add the fullwidth forms through punctuation as in the starter configuration if your headings use them.

Tabs Versus Spaces¶

Obsidian Linter's "Convert spaces to tabs" turns leading spaces into tabs. rumdl's MD010 enforces the opposite convention and replaces tabs with spaces.

MD010 already leaves tabs inside code blocks alone by default (code-blocks = false). To keep tabs everywhere, disable the rule with disable = ["MD010"]. Nothing in rumdl converts spaces to tabs. Such a rule would be a new opt-in rule and a product decision, not a compatibility fix, because it reverses a rule that every other rumdl user relies on.

Candidate Rules¶

These are the rows above that a file linter could legitimately own. They are listed so that a request for one arrives with the mapping already done; they are not commitments.

• Empty list markers (a - or 1. with nothing after it)
• Blank lines around blockquotes
• Blank lines around math blocks
• Footnote reference placement after punctuation
• Footnote re-indexing ([^3] becomes [^1] when it is the first reference)
• Moving footnote definitions to the end of the document
• Front matter title and aliases derived from the file name

YAML value formatting (array style, deduplication, escaping, tag formatting) and the CJK spacing rules are further from what rumdl does today and would need a design of their own.

See Also¶

• Obsidian Flavor - the syntax the obsidian flavor recognizes and how rules adapt to it
• obsidian-rumdl - the Obsidian plugin that runs rumdl inside a vault
• Comparison with markdownlint - for users coming from markdownlint
• Comparison with mdformat - for users coming from mdformat
• Rules Reference - the complete list of rumdl's 82 rules
• Obsidian Linter documentation - the rule reference this page was verified against