Log a warning when an containeritemcomponent is added outside a container

It regularly happens that trainees add a hst:containercomponent to the pages configuration, but make a mistake and add an hst:containeritemcomponent instead. Then the Channel Manager then does not show the container (of course), but there is no warning either. Please add a warning about this situation. Something like: WARN "Found a hst:containeritemcomponent at path /x/y/z that is not the childnode of an hst:containercomponent. This component will not be rendered." (Maybe it should be INFO instead of WARN?).
The message should not be issued of course when the item is in the catalog (child of hst:containeritempackage node).