Editor user interface
Block Indent/Unindent
With the mouse, select a number of lines (more than 1). It is not
necessary to select the full length of the first or last line, any portion of
those lines will do. Press TAB to indent 1 tab stop further. Press
shift+TAB to unindent one tab stop.
Tip: to force the line's left edge to line-up, unindent until all lines are at the margin (now lined up) and then indent as needed.