No, you can't hide them. The option exists in the right-click menu, but when you select it, the option is not hidden : it's still at the same place with white characters in the name, occupying a large place. In a professional environment where you need a consistent appearance of documents, it's really problematic. The only way I've found is to group all styles to avoid in a specific tree name "Do not use" but it's not a right solution. I can't understand why a "table of contents" for example cannot be generated without applying forcefully a bunch of styles, but Okay, let's say it's mandatory. But there are so many uneditable styles! If it's impossible to delete them, is it possible to have them really hidden in such a way that they're really _not_ accessible, like the way it's possible in Calc with Columns, Rows, Sheets, etc.? Ideally, the revert of hiding could be protected by a password. In this case, You could prepare _very_ nice templates in which "technical" styles are used but hidden and "user" styles are presented in a very limited tree.