Sentence:  Some years later, in his Autobiography, Douglas gave a significantly different version of events: My own evidence on this point is obscured by the fact that, as I did not know of the existence of the <WSD>De Profundis</WSD> MS. 
Meaning of the word marked with <WSD> tags:  A letter to Lord Alfred Douglas written by (Oscar Wilde) while he was imprisoned for gross indecency (homosexual acts). The title is a reference to the 130th psalm.