  In the classical knot theory there is a well-known notion of descending
diagram. From an arbitrary diagram one can easily obtain, by some crossing
changes, a descending diagram which is a diagram of the unknot or unlink. In
this paper the notion of descending diagram for knots and links in the real
space is extended to the case of nonoriented knots and links in the projective
space. It is also shown that this notion cannot be extended to oriented links.
