[see also: sign] The mark over an element denotes that it has been omitted.
[see also: indicate, label] The arrow marks the direction of the resulting flow.
The greatest element is marked with a dot.
In Figure 2, the set A is marked by a square with a small triangle on top.
Number the successive segments of the boundary line between A and B (marked thickly in the picture) with the numbers 0,1,...,n, starting at the bottom.
a marked difference [= obvious, noticeable]