765 ILCS 605/26
The use of limited common elements may be transferred between unit owners at their expense, provided that the transfer may be made only in accordance with the condominium instruments and the provision of this Act. Each transfer shall be made by an amendment to the declaration executed by all unit owners who are parties to the transfer and consented to by all other unit owners who have any right to use the limited common elements affected. The amendment shall contain a certificate showing that a copy of the amendment has been delivered to the board of managers. The amendment shall contain a statement from the parties involved in the transfer which sets forth any changes in the parties' proportionate shares. If the parties cannot agree upon a reapportionment of their respective shares, the board of managers shall decide such reapportionment. No transfer shall become effective until the amendment has been recorded. Rights and obligations in respect to any limited common element shall not be affected, nor shall any transfer of it be effective, unless a transaction is in compliance with the requirements of this Section.
Each limited common element may be identified on the plat by the distinguishing number or other symbol of the unit or units to which it is assigned, and its location in respect to the unit or units may also be shown or may be otherwise located in the declaration.
765 ILCS 605/26