DMS-REQ-0030 discussion is misleading

The discussion attached to DMS-REQ-0030 says:

The World Coordinate System for visits will be expressed in terms of a FITS Standard representation, which provides for named metadata to be interpreted as coefficients of one of a finite set of coordinate transformations.

This is misleading: we won't use a “FITS standard representation”. Suggest just dropping that from the text, so it reads:

The World Coordinate System for visits will be expressed in terms named metadata to be interpreted as coefficients of one of a finite set of coordinate transformations.