I'm creating an ultra-challenging scenario that combines multiple complex patterns:
1. ISBN numbers in different valid formats (10 and 13 digit) with optional hyphens/spaces
2. Valid IPv6 addresses with different representations (full, compressed with ::)
3. Time stamps with optional microseconds and different timezone formats
4. Look-alike patterns that shouldn't match
This will require:
- Complex alternation and grouping
- Precise negative lookahead/lookbehind
- Careful handling of optional co... (truncated)