I press "Tab, Tab, Tab, Left, Delete" to get the required indentation. After saving the file I see "^I ". If I press "Space" 11 times instead I see " ".
How to make vim stop introducing new hard tab characters (without changing user-perceived indentation behaviour or mangling existing hard tabs)?
There are a lot of confusing smarttabs, shiftwidths, tabstops and other options. How to do it right?