AcDbMatchProperties is an ObjectARX class specifically designed to serve as a protocol extension base class that provides entity support for the MATCHPROP command. (See the AutoCAD Command Reference for information about MATCHPROP.) The default protocol extension class for AcDbEntity allows copying of color, layer, linetype, and linetype scale properties from one entity to another. It is, nevertheless, preferable to implement AcDbMatchProperties as a protocol extension class for all custom objects derived from AcDbEntity, to provide full support for MATCHPROP. If the default protocol extension class is overridden with AcDbMatchProperties, it must include functions to copy the base class properties as well.