error (enabled by default).
* `indent-with-non-tab` treats a line that is indented with 8 or more
space characters as an error (not enabled by default).
+* `tab-in-indent` treats a tab character in the initial indent part of
+ the line as an error (not enabled by default).
* `blank-at-eof` treats blank lines added at the end of file as an error
(enabled by default).
* `trailing-space` is a short-hand to cover both `blank-at-eol` and