EP format when saving pictures
If you try to save a picture from any graphical window of SCIA Engineer (right-click in the graphical window and choose 'Save image/picture to file), you will find (among others types of formats) EP3, EP2, EPD.
Which ones are available, depends on the kind of window.
With format EP2 it is possible to export contents of the 2D window (for example in the cross-sections database manager).
Format EP3 can be used for export from a 3D window (normal SCIA Engineer graphical window, gallery, etc.).
Format EPD is a window of a paperspace. All formats can be inserted to a paperspace with keeping the original sense, that's a main reason of existence of those formats. (for example EP3 works as fully 3D on paperspace, including lateral change of view direction, hidden lines removal etc.).