A simple mod which adds a "null" item/entity which cannot be crafted or constructed. It is intended for use in splitter filters to stop items from traveling onto an unused path, or in blueprints to mark areas which should be empty.
For greater convenience, use the Filter Helper mod and set null as the default item to always be shown on splitters.
The icon can always be pipetted from Factoriopedia, but if you want it to appear in the splitter filter selection menu without using the above mod, enable the "show all items in selection lists" feature from settings -> interface -> interaction.
Related mods: