Adobe's InDesign application offers many ways of measuring position on the page. One of these is with standardized units known as "picas." When set to picas, InDesign displays two numbers separated by a "p" in the X and Y coordinates that are located at the far left of the control panel at the top of the screen. The readout "p0" indicates that a given location on the document is at an even number of picas. For example, the value "1p0" is exactly 1 pica.
InDesign is a desktop publishing program used to create books, posters, fliers and other print documents. Measuring the page in picas gives designers a convenient way of positioning items according to the size of the text. This takes out the guesswork and conversion calculations resulting from using inches or other standard measurements.
One pica is equal to 12 points or one-sixth of an inch. This is why the X coordinate and the Y coordinate each require a number before the "p" and after the "p." The first is the number of picas, while the second is the number of points beyond the number of picas indicated. For instance, 10p6 is 10 picas and 6 points.
InDesign allows users to change the measurement standard with a simple keyboard shortcut. PC users can do this by pressing the "Ctrl" and "K" keys. Mac users push the "Command" and "K" keys. This opens InDesign's preferences window. In the left-hand column, there is an option labeled "Units & Increments." Selecting this opens the Units preferences. Here, users can choose between point, picas, inches, inches decimal, millimeters, centimeters, ciceros, agates or pixels.
The horizontal and vertical, X and Y, axis do not have to use the same type of unit. When working with InDesign, it's important to verify that the axes are set to the same unit, unless you intend otherwise, as this can cause confusion particularly when precise positioning is necessary. InDesign displays a unit abbreviation beside the values in the X and Y coordinates.