In this subchapter:
(1m) “Department” means the department of revenue.
(2m) “File” means mail or deliver a document that the department prescribes to the department or, if the department prescribes another method of submitting or another destination, use that other method or submit to that other destination.
(3) “Last day prescribed by law” means the unextended due date of the return or of the claim made under subch. VIII. 16671.738 INCOME AND FRANCHISE TAXES (3d) “Pass-through entity” means a partnership, a limited liability company, a tax-option corporation, an estate, or a trust that is treated as a pass-through entity for federal income tax purposes.
(3e) “Pass-through item” means a tax-option item under s. 71.34 (3) or an item of income, gain, loss, deduction, credit, or any other item that originates with a pass-through entity and is required to be reported by one or more pass-through members under this chapter.
(3f) “Pass-through member” means a person who is a partner in a partnership, member of a limited liability company, shareholder in a tax-option corporation, beneficiary of an estate or a trust, or any other person whose tax liability under this chapter is determined in whole or in part by taking into account the person’s share of pass-through items, directly or indirectly, from a passthrough entity.
(4) “Sign” means write one’s signature or, if the department prescribes another method of authenticating, use that other method.