Hi Arthur and thanks, but this Chuck have found and used already.
This option is only to hide the document tab IF only one document is open. Then the tab is hidden.
(call it "Auto-Hide single Document Tab" without trailing 's')
If this is disabled,
an tab is shown even for an single open document,
and more tabs are shown if there are more documents open.
If his is enabled,
there is no tab shown if an single open document is open only,
and more tabs are shown if there are more documents open.
(and the high of the doc window is re-sized always, that's why i don't like this feature)
As i understood Chuck, he wants never ever to see tabs, nor an single neither multi tabs.
Something like VI / VIM,
where you can have one window only
but many docs open (buffers, here documents)
but see only one buffer at time, and switch to other buffers at need.