Using PANOSE Numbers
TrueType font files include PANOSE numbers, which applications can use to choose a font that closely matches their specifications. The PANOSE system classifies faces by 10 different attributes. For more information about these attributes, see PANOSE. A PANOSE structure is part of the OUTLINETEXTMETRIC structure (whose values are filled in by calling the GetOutlineTextMetrics function).
The PANOSE attributes are rated individually on a scale. The resulting values are concatenated to produce a number. Given this number for a font and a mathematical metric to measure distances in the PANOSE space, an application can determine the nearest neighbors.