MNO could mean the telephone number 6 (Jess on the site discussion pages). "I think that the telephone number is MNO and stops there (6). She doesn't want to call anymore" (M on the site discussion pages). Another explanation is that it represents police terminology for types of death "Murder, Natural death and Occasional death, though Kane has forgotten one letter, which is S, for Suicide" (site visitor Frida (Crave).