Where the only GM work in the facility is with uninfected Drosophila (Sophophora) melanogaster, other rooms or corridors, certified or not, may serve as the anteroom, on condition that their doors and windows are kept closed or are fitted with fine mesh able to stop animals, invertebrates included, from getting in or out. Whatever space acts as the anteroom must have measures to monitor for and control escaped flies. The guideline suggests, for example, traps, routine checks, accounting for live and trapped invertebrates and ways of drawing invertebrates away from doors, and suggests writing the procedures down.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.