Should be able to add and edit "type" attributes on <rdg> element.

[d-flood]

This could be done in the collation editor, but then readings would be regularized. Since the open-cbgm can filter based on "type" attributes, it is better to present the actual readings in the apparatus but retain the ability to choose whether to ignore or include common spelling variations and nonsense readings when tabulating coherence.

[d-flood]

Done!