Actually this mostly applies to {link: http://www.vim.org vim}, but... 
 
CVSTrac source uses two spaces for indentation, no tabs. Spaces for indentation 
is more typical of Emacs, rather than vi. 
 
In order to edit CVSTrac source with vi, you'll want the following options 
defined: 
 
  :set expandtab 
  :set tabstop=2 
  :set shiftwidth=2 
 
for convenience, a {link: /cvstrac/getfile/cvstrac/.vimrc .vimrc} file is 
provided in the CVSTrac source which does precisely this. In order to use it, 
you need to 
 
  :set exrc 
 
in ~/.exrc or ~/.vimrc. Note that the _exrc_ option is a potential security 
risk since _.vimrc_ files can run shell scripts and such. Know and trust your 
source before enabling this.