I have a field on the account that is showing as required when you're in edit mode on the account.  In setup, the field is not required.  It is unique and its set as external id.  I created another field as unique and external id and that didnt make it required.  What is making this field required?

I have a field on the account that is showing as required when you're in edit mode on the account.  In setup, the field is not required.  It is unique and its set as external id.  I created another field as unique and external id and that didnt make it required.  What is making this field required?