I'm creating an extremely difficult challenge that combines multiple complex pattern types requiring advanced regex techniques. This includes:
1. Various UUID formats with subtle differences (some valid, some invalid)
2. Credit card numbers with different separator styles (some with valid checksums, some not)
3. Complex date/time formats with timezone variations
4. Mixed IPv6 addresses with different notations
5. API tokens with specific patterns
6. URLs with query parameters and fragments
7. Ve... (truncated)