Indicate things to be removed in version 2.0

autoload/ale/statusline.vim

@@ -1,6 +1,8 @@
 " Author: KabbAmine <amine.kabb@gmail.com>
 " Description: Statusline related function(s)
 
+" remove in 2.0
+"
 " A deprecated setting for ale#statusline#Status()
 " See :help ale#statusline#Count() for getting status reports.
 let g:ale_statusline_format = get(g:, 'ale_statusline_format',
@@ -96,6 +98,8 @@ function! s:StatusForListFormat() abort
     return l:res
 endfunction
 
+" remove in 2.0
+"
 " Returns a formatted string that can be integrated in the statusline.
 "
 " This function is deprecated, and should not be used. Use the airline plugin