The "depth" field in a work request is empty unless the record is part of a display of dependencies of the records selected for a queue listing. In that case, it's a representation of depth within the dependency. The depth is usually represented as "|" repeated appropriately. The one exception when is when the "depth" field is specified immediately before the "subject" field in a queue listing, in which case it's repeated blanks, prepended to the subject.
E.g. if the fields displayed are: serial_num, depth, depth, subject, then a queue listing would be of the form
and so on.
1 Selected Subject 2 | First Dependency #1 3 | Second Dependency of #1 4 || First Dependency of #3
When specifying this field in a customized display, use the name "depth". It cannot be effectively used for a customized sort; and it doesn't result in a complaint as it should. It only works when displaying dependencies of a selected it.