HP PCL/PJL reference (PCL 5 Printer Language) - Technical Reference Manual Part I

6-4 Cursor Positioning EN
Decipoints
In PCL terminology, a decipoint is 1/720 inch or one-tenth of a PCL
point (a PCL point is exactly 1/72 inch as opposed to a typographic
point which is approximately 1/72 inch).
Columns & Rows
The width of a column is defined by the current horizontal motion
index (HMI), as described under “Horizontal Motion Index (HMI)
Command” in Chapter 5. The distance between rows is defined by the
current vertical motion index (VMI), as described under “Vertical
Motion Index (VMI) Command” in Chapter 5. HMI is the distance
between consecutive characters. VMI is the distance between
consecutive lines of text. HMI and VMI are described in more detail in
Chapter 5.
HP-GL/2 has its own coordinate system and units. For additional
information about the HP-GL/2 coordinate system and units, refer to
Chapter 17, An Introduction to HP-GL/2 Vector Graphics.