Você pode encontrar as respostas na especificação da Lixeira do FreeDesktop.org :
Alguns trechos:
$topdir/.Trash-$uid
directory is to be used as the user's trash directory for thisdevice/partition
.$uid
is the user's numeric identifier.The
$trash/files
directory contains the files and directories that were trashed.The
$trash/info
directory contains an “information file” for every file and directory in$trash/files
.
Não há referência ao diretório expunge
, no entanto.