you are right in legal terms ( and im sure you know it )
A formal separation, also called a legal separation, is approved by the courts and can have an effect on marital property and taxes. While separated you remain legally married and are not allowed to remarry. You must get a divorce to be eligible to remarry.
in sequence you can say separated when only separated is mentioned and when legally separated you put married ,and this is where the letter of explanation will clarify the matter again with any supporting documents