24.4 Convenience Features for Indentation

The variable tab-always-indent tweaks the behavior of the <TAB> (indent-for-tab-command) command. The default value, t, gives the behavior described in Indentation. If you change the value to the symbol complete, then <TAB> first tries to indent the current line, and if the line was already indented, it tries to complete the text at point (see Symbol Completion). If the value is nil, then <TAB> indents the current line only if point is at the left margin or in the line's indentation; otherwise, it inserts a tab character.

Electric Indent mode is a global minor mode that automatically indents the line after every <RET> you type. This mode is enabled by default. To toggle this minor mode, type M-x electric-indent-mode. To toggle the mode in a single buffer, use M-x electric-indent-local-mode.