A FORTRAN keyword dictionary, or word list, made to use specially with vim's built-in dictionary completion.
au Bufred, BuFNewFile *f, *f90, *f95 set filetype=fortran
This sets a filetype called "fortran" for files that end with .f
, .f90
, .f95
au FileType fortran set dictionary+=/path/to/.vim/dict/fortran
set dictionary+=/path/to/.vim/dict/fortran
tells vim to use the file you're pointing as a dictionary.
au FileType fortran
tells vim to only set said config when you're working with fortran file type, hence the dictionary completion will not work when using other file types.
Vim's :help dictionary
recommends you to not just comment the line or delete it, nor to just delete the file, but insted to use
dictionary-=/path/to/dictionary