Some MacOS users have very cluttered Docks & wish they could organize them without removing any App icons from the mix.
This snippet will add an empty "spacer" that you can drag around and use to separate icons into groups! See example.
Paste this into your Terminal. Run the command for additional placeholders!
defaults write com.apple.dock persistent-apps -array-add '{tile-data={}; tile-type="spacer-tile";}'; killall Dock;
Note: Your wallpaper & Dock will briefly flicker. This is expected!
Just drag the empty slot off your Dock -- just like removing any other icon!