Pre-Mind Mapping is just something I accidentally made up. It's where you use the table of contents to make a mind map before you activate so when you come across something you want to remember you already have a visual map of where you can place it. Like if you didn't know where Philadelphia is and I told you it was in the SouthEast corner of Pa - you would mentally see a map of Pa and "put" Philly where it belongs in your mind. If you don't have a mental map of PA in the first place you can't do that. When I make them I leave branches and blank spaces so I can mentally "fill them."
