It is sometimes useful to generate headings or notes without actually plotting a chart.

chNul

Example
Typically you would use this (see Twopies in the collection of multiple charts) when several small charts share the same screen, but you want them all under one heading.

chSet ('hstyle' 'left')('Head' 'Two Piecharts;to follow')
chNul

It can also be used (see Intercepts in the collection of multiple charts) when two separate charts share a single key.