765 ILCS 40/2
As used in this Act:
"Adverse instrument" means any document, instrument, or paper that adversely affects, but does not convey, the fee title to registered land, and the validity of which is not dependent upon consent by an owner of the registered land or some person claiming by, through, or under that owner. Adverse instruments include, but are not limited to, mechanics' lien claims, memoranda of judgment, and lis pendens notices. Adverse instruments do not include sheriff's deeds, marshal's deeds, or tax deeds.
"Voluntary instrument" means any document, instrument, or paper that either conveys the fee title to registered land or affects title to registered land and the validity of which is dependent upon consent by an owner of the registered land or some person claiming by, through, or under that owner. Voluntary instruments include, but are not limited to, deeds, including tax deeds, sheriff's deeds, and marshal's deeds, mortgages, assignments of mortgage, leases, and grants of easement or license.
"Registered land" means real property and interests in real property, the title to which has been registered under the Registered Titles (Torrens) Act.
"Registrar's certification of condition of title" means a document, prepared manually or by data processing equipment, that contains the number of the certificate of title, name of the owner, permanent real estate index number, legal description of the land, and nature of the estate of the owner and by memorial contains a description of all estates, easements, encumbrances, liens, interests, and charges to which the estate of the owner is subject; in the event title to the land is held in trust, it shall so state; and if the land is subject to any condition or limitation, it shall state the nature and character of the condition or limitation.
765 ILCS 40/2