Auto-Indent
When this option is selected, pressing the Return key in new windows automatically inserts spaces or tabs to indent the new line to the same level as the previous line. To temporarily invert the sense of the Auto Indent option while typing, hold down the Option key as you press the Return key.
Shift Left / Shift Right
These commands indent or outdent the selected text by one tab stop. If there is no selection, this command works on the current line. Hold down the Shift key while choosing these commands, to have TextWrangler indent or outdent the text by one space instead of one tab stop.
TextWrangler also entabs and detabs on the fly as you shift text. For example, if the selected text is indented one tab stop and you apply Shift Left One Space, the tab will be converted to spaces and the text will be outdented one space. If you then apply Shift Right One Space, the spaces will be converted back to a single tab.
Soft Wrapping with Indentation
You can control how TextWrangler indents soft wrapped text by means of the Soft Wrapped Line Indentation option in the Editing: General preference panel. Choose Flush Left to have all lines of each paragraph below the first wrap flush to the left margin of the window. Choose First Line to have all subsequent lines of a paragraph wrap to the same indent level as its first line. Choose Reverse to have all subsequent lines of each paragraph wrap indented one level deeper than its first line.