aid: gitignore:rules
name: .gitignore Rules
description: Pattern syntax and processing rules for .gitignore files used by Git.
rules:
  - name: Blank Lines Ignored
    description: A blank line matches no files; commonly used as a separator for readability.
  - name: Comment Lines
    description: A line starting with # is a comment; escape with \# to match files starting with #.
  - name: Trailing Spaces
    description: Trailing spaces are ignored unless escaped with a backslash.
  - name: Negation Pattern
    description: A prefix ! negates the pattern, re-including a file matched by a previous pattern.
  - name: Directory Pattern
    description: A trailing slash makes the pattern match only directories.
  - name: Anchored Pattern
    description: A leading slash anchors the pattern to the directory of the .gitignore file.
  - name: Glob Wildcards
    description: Supports * (any except /), ? (single char), and [abc] character classes.
  - name: Double Asterisk
    description: ** matches across directory boundaries; leading **/ matches in any directory.
  - name: Excluded Parent Directory
    description: A file cannot be re-included if its parent directory is excluded.
  - name: Hierarchical Files
    description: .gitignore files at deeper levels override patterns from parent directories.
  - name: Global Excludes
    description: core.excludesFile in git config defines a system-wide ignore file.
  - name: Tracked Files Unaffected
    description: .gitignore only affects untracked files; tracked files require git rm --cached.
  - name: Multiple Locations
    description: Patterns can live in repo .gitignore, .git/info/exclude, or core.excludesFile.