Test, validate and match regular expressions
This regex matches Federal Acquisition Regulation (FAR) clause or provision entries in government contract documents. It captures the FAR reference number (e.g., 52.223-4), followed by either the complete clause text ending with '(End of clause)' or '(End of provision)', or a '[Reserved]' designation. Useful for parsing and extracting FAR clauses from solicitations, contracts, and acquisition documents.