Here's a quirky little one:
QUERY (select by keyword0 AT LEVEL QONLY
posts TRACK on the command line instead of QONLY.
It doesn't really matter because when you then press enter the command is rejected anyway ('Error: Channel List is Empty'), which is probably also wrong, but this is wrong.
(Working around QUERY not selecting without pressing enter, you have to go:
QUERY (select by keyword) ENTER
AT LEVEL QONLY
which does work properly)