In the Editor users should be able to a) enter XY coordinates of points and vertices in decimal degrees (DD) at any time without having to unproject their projected data frame so it uses a GCS b) enter XY coordinates in degrees decimal minutes (DDM) and degrees minutes second s (DMS)
To enter coordinates in Decimal Degrees when working with a projected data frame, go to View > Data Frame Properties dialog Coordinate System tab and choose a Geographic Coordinate System (GCS) for your data frame so that the map units are in decimal degrees. When you enter coordinates in the editor, such as in the Absolute XY dialog accessed by pressing F6 when sketching, you can specify unit abbreviations to enter coordinates in different units than the map units of the data frame, but decimal degrees are not supported. To see a list of the ones that are supported, press F1 when you are in a dialog like the Absolute XY dialog.