Recently in a thread I changed the default 'Re: ...' subject of my followup (to one of my own posts) to 'Details' (because in fact I was giving additional details to the OP which I wanted to stay concise and self-contained).
Then I've been warned by another poster not to do so and pointed to some documentation about how to choose effective subjects.
Now, having spent some time in technical NGs, where this is even more of a necessity, I am well aware of how important it is, generally. But here threads are kept together regardless of any subject modification. So the question is: provided that you choose an effective subject for the first node (i.e., loosely speaking, for the thread as a whole), is it such a Bad Thing(TM) to change the subject of individual nodes within that thread to something less informative?
More clearly: I would never ever even think of creating a new discussion in whichever section with a node called 'details'. But if in the discussion 'Interesting technique to do xyz' I put a node called 'details', it's obvious that I'm talking about details regarding 'Interesting technique to do xyz'!