The E system, used in some buildings with group showers and gender-neutral bathrooms, lets others know who is allowed in the shower at that time. This lets whoever is already in the shower decide whether he/she wants others coming in or not.
The E has four orientations:
- E: everyone (men, women, whoever) can jump in the shower
- W: only women
- M: only men
- 3: "Me, myself, and I" — no one else until whoever's showering is done