Rule - MD050

Property	Value
Aliases	md050, strong-style
Autofix Available	No
Enabled By Default	Yes

Summary

Ensure consistent strong emphasis style throughout the document.

Reasoning

Readability

To maintain a uniform appearance and improve readability, the character sequence used for strong inline emphasis (e.g., asterisks vs. underscores) should remain consistent throughout a document or set of documents.

Examples

Failure Scenarios

This rule triggers when there is inconsistent use of inline strong emphasis blocks.

This is **one** strong emphasis.

This is __another__ strong emphasis.

Explanation: This example fails because the first line uses asterisks (**) for strong emphasis while the second line uses underscores (__). With the default consistent style, the first strong emphasis block sets the expected style to asterisks. The subsequent use of underscores violates this consistency requirement.

Unlike the previous example, which relies on the default consistent style, this scenario violates the rule when the style configuration is explicitly set to asterisk. Even if all strong emphasis blocks use underscores consistently among themselves, they fail the rule because underscores are not permitted in this strict mode.

This is __one__ strong emphasis.

This is __another__ strong emphasis.

Explanation: This example fails because the configuration style is set to asterisk, which mandates that only asterisks (*) may be used for strong emphasis. Although both blocks use underscores consistently, underscores are prohibited in this mode.

Unlike the previous example, which demonstrated a violation of the asterisk configuration, this scenario violates the rule when the style configuration is explicitly set to underscore. Even if all strong emphasis blocks use asterisks consistently among themselves, they fail the rule because asterisks are not permitted in this strict mode.

This is **one** strong emphasis.

This is **another** strong emphasis.

Explanation: This example fails because the style configuration is set to underscore, which mandates that only underscores (_) may be used for strong emphasis. Although both blocks use asterisks consistently, asterisks are prohibited in this mode.

Correct Scenarios

This rule does not trigger when the character sequence for strong emphasis blocks is consistently specified within the document:

This is **one** strong emphasis.

This is the **same** strong emphasis.

Explanation: This example passes because both strong emphasis blocks use asterisks (*). This is consistent with the default consistent style, which adopts the style of the first strong emphasis block encountered.

Unlike the previous example, which relied on the default consistent style, this scenario demonstrates compliance when the style configuration is explicitly set to underscore. All strong emphasis blocks use underscores, satisfying the strict configuration requirement.

This is __one__ strong emphasis.

This is __another__ strong emphasis.

Explanation: This example passes because the configuration style is set to underscore, which mandates that only underscores (_) may be used for strong emphasis. Both blocks use underscores, satisfying this requirement.

Unlike the previous example, which demonstrated compliance with style set to underscore, this scenario shows compliance when style is explicitly set to asterisk. All strong emphasis blocks use asterisks, satisfying the strict configuration requirement.

This is **one** strong emphasis.

This is **another** strong emphasis.

Explanation: This example passes because the configuration style is set to asterisk, which mandates that only asterisks (*) may be used for strong emphasis. Both blocks use asterisks, satisfying this requirement.

Fix Description

Because the rule is style-sensitive, the tool cannot safely determine which emphasis marker (** or __) the author intends when only a single type is present. Automatically choosing one could change the document's intended formatting, so no autofix is applied.

Configuration

Prefixes
plugins.md050.
plugins.strong-style.

Value Name	Type	Default	Description
enabled	boolean	True	Whether the Rule Plugin is enabled.
style	string	consistent	Style of inline strong emphasis block characters expected in the document.

Valid Styles

Style Name	Description
consistent	The first inline strong emphasis block in the document specifies the style for the rest of the document.
asterisk	Only asterisks are to be used for inline strong emphasis block elements.
underscore	Only underscores are to be used for inline strong emphasis block elements.

Origination of Rule

This rule is largely inspired by the MarkdownLint rule MD050.