Regex Editor & Tester

Matches lines that consist solely of a four-level hierarchical numbering pattern (e.g., 1.2.3.4 or 12.3.4.5), commonly used to identify subsubsub sections in legal documents like constitutions or bylaws. With the multiline flag, it checks each line independently, ensuring the entire line is exactly that pattern. Useful for extracting or validating section references in structured documents.