I'm creating an exceptionally difficult challenge that combines multiple complex patterns:
1. Mix of IPv6 addresses (both compressed and full forms) with similar-looking but invalid formats
2. Complex product codes with strict format requirements
3. Custom date formats with various separators and validation needs
4. Look-alike patterns that should be excluded
This will require:
- Careful handling of hex digits and colons in IPv6
- Complex validation rules for the product codes
- Proper handling ... (truncated)