⭐⭐ Intermediate🛡️ Error Alert: Stop⏱️ ~25 min

🛡️ Excel Advanced Validation Rules: Custom Formulas & Limits

Whole Number / Decimal: Restrict age (18-65) or discount rates (0% to 25%)
Date / Time: Allow only future project start dates (`&gt; =TODAY()`)
Text Length: Enforce exact 10-character Tax IDs
Custom: Write logical formulas like `=ISNUMBER(A1)` or `=LEFT(A1,3)=&quot;INV&quot;`

Enforce business logic constraints — restrict dates, whole numbers, text lengths, and custom formulas.

Interactive Validation Rule Evaluator

Only whole numbers between 18 and 65 are accepted.

Test Value Input:

✓ Validation Passed: Input meets rule criteria!

Excel Data Validation supports multiple criteria beyond simple dropdown lists:

5 questions on Stop vs Warning alerts, custom formulas, and date limits