You are playing the Regex Pattern Matcher game against o3-mini - (high).

Game history:
Turn 1: o3-mini - (high) proposed text with target items: ["alice.smith+promo@sub-example.co.uk","+1 (800) 555-0199","2023-10-05","29/02/2020","GH-321-GH"]
gpt-4o-mini provided pattern: ([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}|\+\d{1,3} \(\d{3}\) \d{3}-\d{4}|\d{4}-\d{2}-\d{2}|\d{2}/\d{2}/\d{4}|([A-Z]{2})-\d{3}-\1) (SUCCESS)

Current turn: 2 of 10
You are the PROPOSER.

Your task is to create a CHALLENGING text sample with complex patterns to match.
Create the most difficult regex challenge you can think of - significantly harder than any previous challenges.

Guidelines for creating a DIFFICULT challenge:
1. Use complex patterns that require advanced regex techniques to match.
2. Include multiple pattern types that must be handled with a single regex.
3. Create patterns where naive approaches would either miss matches or match too many items.
4. ADVANCED PATTERNS to consider:
   - Mixed forma... (truncated)