ยง 6501. Notice of pendency; constructive notice. A notice of pendency may be filed in any action in a court of the state or of the United States in which the judgment demanded would affect the title to, or the possession, use or enjoyment of, real property, except in a summary proceeding brought to recover the possession of real property. The pendency of such an action is constructive notice, from the time of filing of the notice only, to a purchaser from, or incumbrancer against, any defendant named in a notice of pendency indexed in a block index against a block in which property affected is situated or any defendant against whose name a notice of pendency is indexed. A person whose conveyance or incumbrance is recorded after the filing of the notice is bound by all proceedings taken in the action after such filing to the same extent as a party.