## Excel Data validation specific characters only

Set criteria to accept specific characters only To use data validation to allow a list of specific characters only, you can use a rather complicated array formula based on the COUNT, MATCH, and LEN functions. Formula =COUNT(MATCH(MID(A1,ROW(INDIRECT (“1:”&LEN(A1))),1),allowed&””,0))=LEN(A1) Explanation In the example shown, data validation is applied with this formula: =COUNT(MATCH(MID(B5,ROW(INDIRECT (“1:”&LEN(B5))),1),allowed&””,0))=LEN(B5) where “allowed” is …