How can I ensure that a field is blank for some account types, and mandatory for others?

Hi Pranav,

we can do this by following ways:-

1)OR(logical1, logical2...) and replace any number of logical references with the expressions you want evaluated.

2)AND(logical1, logical2...) and replace any number of logical references with the expressions you want evaluated.

3)ISPICKVAL(picklist_field, text_literal) and replace picklist_field with the merge field name for the picklist; replace text_literal with the picklist value in quotes. text_literal cannot be a merge field or the result of a function.

4)NOT(logical) and replace logical with the expression that you want evaluated.

Eg:-

AND(
OR(
ISPICKVAL(Type, "Client"),
ISPICKVAL(Type, "Client - Group Contract")
),
ISPICKVAL(Customer_Management__c, "")
)