+@cindex Fortran fixed form and free form
+@cindex Fortran 77 and Fortran 90, 95, 2003
+@findex f90-mode
+@findex fortran-mode
+ Fortran mode is meant for editing ``fixed form'' (and also ``tab
+format'') source code (normally Fortran 77). For editing more modern
+``free form'' source code (Fortran 90, 95, 2003), use F90 mode
+(@code{f90-mode}). Emacs normally uses Fortran mode for files with
+extension @samp{.f}, @samp{.F} or @samp{.for}, and F90 mode for the
+extensions @samp{.f90} and @samp{.f95}. Customize
+@code{auto-mode-alist} to add more extensions. GNU Fortran supports
+both free and fixed form. This manual mainly documents Fortran mode,
+but the corresponding F90 mode features are mentioned when revelant.
+