I suppose that the language preferences take precedence over the default preferences For example, if you edit a perl script, you have to modify this line of the file ~/.nedit/nedit.rc to suppress autoindent Perl:.pl .pm .p5 .PL:"^[ \\t]*#[ \\t]*!.*perl":[b][color=#FF0000]Auto[/color][/b]:None:::".,/\\\\`'!$@#%^&*()-=+{}[]"":;<>?~|":\n\ will become Perl:.pl .pm .p5 .PL:"^[ \\t]*#[ \\t]*!.*perl"::None:::".,/\\\\`'!$@#%^&*()-=+{}[]"":;<>?~|":\n\