Well, what do you want to know?

This is an extract from the rules that contains much information that will not be of interest to you (combinations etc.).

The interesting bit, about refunds and changes etc. is not quoted (but I think you got this from the BA site, which is a modern marvel for providing information that is useless at the expense of the information you really need). It looks like the fully flexible fares that are available from places like CAI.