What 'default format' does is to apply the (character style) of the document-default style. The style in the docker at the top of the styles list.
Notice that this stuff is much more usable and nice in the development version of KOffice so it will be much easier to figure out what this does.

ps. renamed the topic as you requested

Thanks, Thomas. Maybe the topic might be better with "2.X.X" since it the first group of posts referred to 2.2, though it probably will not matter since the posts are intended to provide a user perspective to you developers, and you are already all ahead of me into the dev. versions.

I'll just forge ahead. I hope other users can chime in, too. What one of us users sees won't always be what another one is looking at.

Thank you, all, for reading the posts on the forum. Interaction between users and developers is one of the things about Free/Open software that satisfies participating users. One also hopes that participation advances the projects through the community of effort.