The pattern is built using alternation (|) to match each specific item exactly:
1. For the emails:
   - "john\.doe@example\.com" - escaping dots as they're special characters
   - "alpha_beta-999@sub\.ex-ample\.co\.uk" - matching the complex email exactly
2. For the phone: "\+1 \(800\) 555-0199" - escaping special characters +,(,)
3. For the date: "2023-12-31" - simple exact match
4. For the code: "CODE-123---AB123" - exact match with literal dashes

The pattern uses ^ and $ anchors within each alternation to ensure no partial matches.