It first appeared with the release of WordPerfect 5.0, and with the release of version 5.1, the format was changed accordingly. It is advised to use the same format version as the version of WordPerfect in which the image will be used. These files can contain bitmaps, line art, and vector graphics. When using an application rather then WordPerfect for viewing a WPG file containing both bitmapped and vector elements, the vector elements will be discarded.
Note: that the WPG specification allows files of up to 256 colors, but WordPerfect itself would not read files of more than 16 colors!