2.1.936 Section 15.30.9, Lines
a. The standard defines chart:lines, contained within [style-chart-properties-attlist]
-
This is supported in core Excel 2007.
-
This attribute applies to the <style-chart-properties-attlist> element of the <chart:chart>, <chart:plot-area>, and <chart:series> elements when the series type is "line", "scatter", or "radar".