This is documentation for Mathematica 5, which was
based on an earlier version of the Wolfram Language.

 Ordering Ordering[list] gives the positions in list at which each successive element of Sort[list] appears. Ordering[list, n] gives the positions in list at which the first n elements of Sort[list] appear. Ordering[list, -n] gives the positions of the last n elements of Sort[list]. Ordering[list, n, p] uses Sort[list, p]. Example: Ordering[c, a, b] . In a numerical list Ordering[list, n] gives the positions of the n smallest elements. Ordering[list, -n] gives the positions of the n largest elements. If there are several smallest elements in list, Ordering[list, 1] will give only the position of the one that appears first. list[[Ordering[list]]] is the same as Sort[list]. Ordering[list, seq] is equivalent to Take[Ordering[list], seq]. Ordering[list, All, p] gives the position at which all elements of list appear in Sort[list, p]. Ordering can be used on expressions with any head, not only List. See Section 1.8.11. See also: Max, Min, Position, OrderedQ, Median. New in Version 4.1.