The pattern is built using alternation (|) to match exactly the required strings:
1. Phone numbers: 
   - "\+1-123-456-7890" for the exact +1 format
   - "01234 567890" for space-separated format
   - "09876-54321" for the shorter hyphenated format
2. Email addresses: Each email is matched exactly to avoid matching invalid ones
3. IDs: Combinations of letters, numbers with separators (-, .)
4. Dates: All three specific date formats

By using alternation and exact matches, we ensure we only match the specified strings and nothing else in the text. The pattern is separated into parts for different types of items, making it more manageable and maintainable.