MD022 - Add blank lines around headings¶
Aliases: blanks-around-headings
What this rule does¶
Checks that headings have blank lines before and after them to improve readability and document structure.
Why this matters¶
- Better readability: Blank lines create visual separation, making content easier to scan
- Clear structure: Spacing helps readers understand the document hierarchy
- Consistent rendering: Many Markdown processors require blank lines for proper formatting
- Professional appearance: Well-spaced documents look more polished and organized
Examples¶
✅ Correct¶
Some introductory text here.
# Main Heading
This is the content under the main heading.
## Subheading
More content follows here.
### Another Section
And even more content.
❌ Incorrect¶
Some introductory text here.
# Main Heading
This is the content under the main heading.
## Subheading
More content follows here.
### Another Section
And even more content.
🔧 Fixed¶
Some introductory text here.
# Main Heading
This is the content under the main heading.
## Subheading
More content follows here.
### Another Section
And even more content.
Configuration¶
Basic configuration¶
[MD022]
lines-above = 1 # Blank lines required above headings (default: 1)
lines-below = 1 # Blank lines required below headings (default: 1)
allowed-at-start = true # Allow headings at document start without blank line above (default: true)
lines-above-mode = "minimum" # "minimum" or "exact" (default: "minimum")
# nested-heading-lines-above = 1 # Blank lines before a heading that directly follows its parent (default: unset)
Spacing before a nested heading¶
Set nested-heading-lines-above to use a different number of blank lines when a
deeper heading directly follows another heading without intervening content.
This value overrides both lines-above for the child and lines-below for the
parent in their shared gap. It accepts a scalar or a six-value array indexed by
the child heading's level.
With this configuration, adjacent parent and child headings have one blank line
between them. A child heading after content in the parent section still uses the
normal lines-above value.
A heading directly follows its parent when it is deeper than the heading before it, sits in the same blockquote or other container, and only these lines come between the two:
- blank lines
- HTML and MDX comments
- block attribute lines, in flavors that recognize them
- div fences, in the Pandoc flavor
Anything else counts as body, including reference definitions and thematic
breaks, so the child gets the normal lines-above value.
In the default lines-above-mode = "minimum", the nested value is a minimum like
every other spacing value: more blank lines between a parent and its first child
still pass. Set lines-above-mode = "exact" to require exactly that many.
MD012 also allows the nested value next to headings, so a nested
value larger than lines-above and lines-below raises MD012's limit around
every heading.
Exact spacing above headings¶
By default, lines-above-mode = "minimum" accepts extra blank lines. Use exact
mode to also report and remove surplus blank lines immediately above headings:
The mode uses the same per-level lines-above values, document-start exceptions,
and inline disables as minimum mode. A value of 0 removes blank lines above
that level where safe; a separator before Setext headings or after HTML blocks
is retained. -1 leaves spacing unrestricted. Spacing below headings retains
its minimum behavior. By default, a gap between adjacent headings satisfies the
larger of the child's lines-above and the parent's lines-below values. When
nested-heading-lines-above is set, its value replaces both requirements for
that gap.
Comment-only lines continue to satisfy the minimum spacing requirement. Exact mode caps the contiguous run of actual blank lines immediately above the heading, or above comments attached directly to it. Earlier gaps between blocks and all comments stay intact. It also preserves blank lines that separate independent blockquotes.
Per-level configuration¶
You can specify different spacing requirements for each heading level (h1-h6) using arrays:
[MD022]
# Different spacing for each level: [h1, h2, h3, h4, h5, h6]
lines-above = [2, 1, 1, 1, 1, 1] # h1 needs 2 blank lines above, others need 1
lines-below = [1, 1, 1, 0, 0, 0] # h4-h6 don't need blank lines below
Use -1 to accept any number of blank lines for a specific level:
[MD022]
lines-above = [-1, 2, 1, 1, 1, 1] # h1 is unrestricted, h2 needs 2 blank lines
lines-below = [1, -1, -1, -1, -1, -1] # h1 needs 1, others are unrestricted
This is useful when you want:
- More space before top-level headings for visual separation
- Less space around deeply nested headings
- Different spacing conventions for different document sections
Automatic fixes¶
This rule automatically adds the required number of blank lines:
- Before headings (except at the start of a document)
- After headings (except at the end of a document)
Lists and code fences directly below a heading¶
lines-below applies before lists, fenced code blocks, and thematic breaks,
just as it does before paragraphs. MD022 enforces this requirement even when
MD032 or MD031 is disabled. When multiple rules require
the same blank line, fixing the document inserts it only once.
HTML comments¶
A line holding nothing but an HTML comment counts as a blank line, so a comment
directly above or below a heading satisfies this rule and rumdl fmt leaves the
document alone:
This keeps a directive comment attached to what it applies to: inserting a blank line there would turn the directive off.
The comment has to have the line to itself. Some text. <!-- note --> is a
paragraph, so a heading written under it is still missing its blank line. A
comment spanning several lines counts at both ends, and the convention holds
inside a blockquote. MD031, MD032 and MD058
read blank lines the same way.
Markdown with Gherkin¶
Under the mdg flavor, MD022 does not require a blank line above a heading that
names a Gherkin structure when the line directly above it is a tag line — a line
containing a backtick-wrapped tag:
Recognition follows Cucumber's `(@[^`]+)` scan. A matching tag may occur
anywhere on the line, and surrounding text or a trailing comment does not
disqualify it.
When the tag line opens the document, Gherkin reads the inserted blank as the Feature line and the Feature collapses into an unnamed node. Lower down the blank leaves the parse intact, and the exemption keeps the tags written against the structure they belong to.
The exemption needs both halves. An ordinary heading such as ## Notes names no
structure and keeps the requirement even below a tag line, a line without a
matching tag is not a tag line, and the requirement below a heading is never
waived.
See Markdown with Gherkin Flavor for the full flavor specification.