Sorting cards

[doc hawk]

paul pondered,

> I'm not sure about this, but do all the cards have the SAME background with the SAME fields (I think they were Category and Title?). If you have mixed backgrounds - I think there may be sort problems sorting on background fields. Again, this is from memory and I could be wrong.

If memory serves, you couldn’t *have* multiple backgrounds, as the background was a stack attribute.

 But then, it’s almost 30 years . . .