Thanks for the replies.
I asked:
What I'm after is a way to be able to change things like colours and line thicknesses just once, and have those changes affect all of the boxes [containg text] of that class. Is cloning the best way to do this?
Bulia suggested:
Don't clone the group - clone only the rect. Made the clone of the rect first, then group rect with text; clone will not be affected, it will only reflect the rect as before. Then you can duplicate the clone as many times as you need to get more clones of the same rect.
OK, I've tried it, and it works. Thanks! Unfortnately it looks as if resizing the clones (i.e. so that they fit the text that they contain) always resizes the box stroke width, even if the "scale stroke width" button is off, so this doesn't really do what I wanted.
Mental suggested:
This is basically what CSS classes are for; I think we do have sufficient CSS support to use them now, but not good UI for CSS yet.
Great, I can do CSS, and "instance of a class" is a more familiar mental model (HTML+CSS, C++) than "duplicate of a clone".
So, I can set a class attribute on things using the XML editor [is there an easier way?] and I can write a CSS stylesheet in a text editor. Can you help me to associate the stylesheet with the document?
Cheers,
--Phil.