Only one enhancements has found its way into GMT 3.3.1. This applies to the -B option. In addition to an axis label, each axis may also set a unit label to be appended to each individual anotation on that axis. This is useful if you want anotations to be, say, 10%, 20%, 30%, etc. The syntax is :,``unit label'': (note the comma flag). Like for labels, the quotes are only needed if the unit label has spaces in it. Normally, a single space is inserted between anotation value and unit. This may be removed by letting the unit begin with - (the minus sign). The unit option is only used with non-geographic projections.