Excel Data Validation Lists
Control allowed input and reduce manual entry errors.
What this solves
Restrict status to Open, Hold, Closed. This pattern is useful when the business question is clear but a generic tutorial is too abstract.
The rule
Use a list source or a formula-based rule.
Open,Hold,ClosedGoogle Sheets: The core pattern is also usable in Google Sheets; exact function support and locale separators can differ.
Real-work checklist
- Define the business key and expected grain before writing the formula, query or markup.
- Test the pattern on a small known sample where you can verify the answer manually.
- Check missing values, duplicates and data types before trusting a large result.
- Scale to the real file or database only after the logic is proven.
Common mistake
Validation improves entry quality but does not clean already-invalid historic data.