Explanation
Data validation rules are triggered when a user adds or changes a cell value.
The UPPER function changes text values to uppercase, and the EXACT function performs a case-sensitive comparison.
The AND function takes multiple arguments (logical conditions) and returns TRUE only when all arguments return TRUE.
The first logical condition compares the value input by the user to an uppercase version of the same value:
EXACT(C5,UPPER(C5)
The second logical condition tests that input to C5 is actually text
ISTEXT(C5)
If both conditions are TRUE, the AND function returns TRUE and input passes validation. If either condition is FALSE, AND returns FALSE and input fails data validation.
Note: Cell references in data validation formulas are relative to the upper left cell in the range selected when the validation rule is defined, in this case C5.
Related formulas
Data validation allow numbers only
Data validation allow text only
Related functions
UPPER Function
The Excel UPPER function converts a text string to all uppercase letters. Numbers, punctuation, and spaces are not affected.
EXACT Function
The Excel EXACT function compares two text strings, taking into account upper and lower case characters, and returns TRUE if they are the same, and FALSE if not. EXACT is case-sensitive.
AND Function
The Excel AND function is a logical function used to require more than one condition at the same time. AND returns either TRUE or FALSE. To test if a number in A1 is greater than zero and less than 10, use =AND(A1>0,A1<10). The AND function can be used as the logical test inside the IF...
