(a) The declaration, any amendment or amendments thereof, any instruments by which the provisions of this chapter may be waived, and every instrument affecting the property or any apartment shall be entitled to be recorded. Neither the declaration nor any amendment thereof shall be valid unless duly recorded.
(b) In addition to the records and indexes required to be maintained by the Recorder of Deeds, said Recorder shall maintain an index or indexes whereby the record of each declaration contains a reference to the record of each conveyance of an apartment affected by such declaration, and the record of each conveyance of an apartment contains a reference to the declaration of the building of which such apartment is a part.