Drain no. D234A56Z
I'm just an anonymous, dirty drain slave - public drain no. D234A56Z. People walk all over me day and night and barely even notice my humble confinement beneath their feet. All I can see is their shoe soles and socks and, if I'm lucky, some of their shoedirt falls off into my menial mouth as they walk past, thus supplementing my meagre drain-prisoner diet.