The pica-point system is used in typography to measure type sizes, tracking, line spacing, columns, lines, areas, and lengths.
The pica-point system is used in all professional layout and DTP software (for example Adobe InDesign ® or QuarkXPress ®).

One pica-point (abbreviated as ppt) is the smallest unit of the American pica-point typographical measurement system.
“MilliPoint” is an app for DTP users that lets them easily convert millimeters into pica points or pica points into millimeters.