- "Indent line or region in proper way for current major mode or insert a tab.
-Depending on `tab-always-indent', either insert a tab or indent.
-
-In most major modes, if point was in the current line's indentation,
-it is moved to the first non-whitespace character after indenting;
-otherwise it stays at the same position in the text.
-
-If a prefix argument is given, also rigidly indent the entire
+ "Indent the current line or region, or insert a tab, as appropriate.
+This function either inserts a tab, or indents the current line,
+or performs symbol completion, depending on `tab-always-indent'.
+The function called to actually indent the line or insert a tab
+is given by the variable `indent-line-function'.
+
+If a prefix argument is given, after this function indents the
+current line or inserts a tab, it also rigidly indents the entire