Defines the indentation of text from the Left and Right margins of the topic editor, and also allows you to set a special indent for the first line, which will be relative to the Left indent.
For example, if the left indent is set to "0.5 cm", and the first line to "-0.5 cm", that will have the effect of a hanging indent of 0.5cm, with the first line flush with the margin.
The ParaLeft element corresponds to the "(Indentation) Left" field, on the "Paragraph" sub-tab, on the "Style Definition" tab, of the Style object.