R005 DuplicateLines

Applies to: Rules files (CLAUDE.md, AGENTS.md, .mdc, .cursorrules, Copilot instructions, GEMINI.md, .windsurfrules)
Severity: Warning (−4 per finding, max −30)
Summary: The same instruction appears more than once.
Flags: Repeated instruction lines (instruction sentence as in R001) of four or more words, ignoring case, whitespace, and list markers. Excluded: headings, code blocks, indented code, horizontal rules, table rows, HTML comments, wrapped continuation lines. Not reported: a line that occurs three or more times (template), a repeat whose previous or next line has the same shape as the line beside the first occurrence, ignoring digits and inline code (repeated block), or a repeat at the same position under section openers of the same kind and level (parallel sections). Section openers: headings, bold-label lines ("**Output Format**:"), and list items with deeper lines under them.
Measured false-positive rate: 17% (1 of 6) and 17% (1 of 6), two judges, ruleset v4. Methodology

Before

- Run tests before commit.
* run tests before commit.

- Run tests before commit.