Chord diagrams, $d$-diagrams, and knots

A method of representing knots, links, and singular knots and links by means of words in a finite alphabet and so-called $d$-diagrams is given. Also a representation of the chord diagram algebra in terms of words in a finite alphabet is considered. This method, unlike coding by Gauss diagrams, allows to consider knots and links simultaneously. An algorithm for recognition diagrams of classical knots in the terms of $d$-diagrams is given.