What does "Indorsement without recourse" mean?

Negotiable Instrument Act Section 52. Indorser who excludes his own liability or makes it conditional:  The indorser of a negotiable instrument may, by express words in the indorsement, exclude his own liability thereon, or make such liability or the right of the indorsee to receive the amount due thereon depend upon the happening of a specified event, although such event may never happen. Where an indorser so excludes his liability and afterwards becomes the holder of the instrument, all intermediate indorsers are liable to him. Illustrations (a) The indorser of a negotiable instrument sign; his name adding the words-- "Without recourse". Upon this indorsement he incurs no liability.