Changes Introduced in Version 2.1

The COFRAME statement has been extended to include specific support for TimeFrame, SpecFrame and DSBSpecFrame co-ordinate systems.
The user coordinate system used to describe positions and shapes within an ARD expression can now refer to a sub-space of the axes defined in the application WCS FrameSet. For instance, if the application is an (RA,Dec,freq) cube, an ARD expression can be used that refers only to the freq axis, in which case the same frequency region will be masked in all (ra,dec) planes.