When your form is setup with the multi-signature field, you will see the following form submission statuses on the leads module:
Incomplete
The form submission contains incomplete mandatory fields.
Incomplete (valid)
The primary parent has signed the form but not yet paid.
Pending signature
The form submission is pending signatures from the subsequent parents added to the form.
Complete
The form submission is completed including signatures from all parents added to the form (as required according to the form settings).
