Marks "are the elements with which the drawing is made. Mark-making is

the broad term used to include all marks that are made visible as a

manifestation of applied or gestural energy.  It is the gestural language of

drawing and marks are the components marks within it. There are an infinite

number of marks possible, and our nomenclature for them is very limited -

lines, dots, dashes, smudges, etc., It is difficult to refer to specific marks, and

know that the term adequately communicates its intended meaning."

From: Maslen, M. & Southern, J. (2011). Drawing projects: An exploration of the language of drawing. Black Dog. (see pages 28-33, emphasis added).

Mark-making (PACEY)

It is only gradually that children early marks transform into early marks and signs that they use to communicate their emergent thinking -  for their early drawings, maps and writing and in contexts that may be understood as mathematical.

The following examples show some of this development:

Taxonomy: categories

The taxonomy