Yes, I know that you are able to use different structure tags. What I wanted is a field for the author base – not to put the authors name/slug in the permalink base for the posts. I'm talking about the options below the posts permalink base on the settings page, where you set the base for category and tags.
WordPress generates special views automatically, for instance where all the posts within a certain category are listed, or all posts with a certain tag. The same is also true for all articles by a special author. These are put under /author/kristofer/ for instance (if you have activated permalinks that aren't like "?p=123"). And then I want to change "author" to something else - just like you can do with category and tags.
Great with a plugin, but I cant understand why it's not there in the settings in WordPress core. It doesn't make sense to have views for some parts where you can choose permalinks base, but not for others.
I had already changed language, so that wasn't the problem either. (And I don't have a multi language site.)