The pattern matches the valid IDs with these components:
1. Starts with "ITEM-" (anchored with word boundary to avoid partial matches)
2. Year component: (202[2-4]) - matches years 2022, 2023, or 2024 only
3. Month component: (0[1-9]|1[0-2]) - matches months 01-12
4. Day component: (0[1-9]|[12][0-9]|3[01]) - matches days 01-31 (simplified approach)
5. Hyphen followed by one of the valid suffixes: "ALPHA", "BETA", "GAMMA", or "DELTA"
6. Ends with a word boundary to prevent matching items with extra characters

The word boundaries (\b) at the start and end ensure we only match complete IDs, not partial matches. The pattern captures exactly the format of the valid IDs while excluding the invalid ones described in the text.