patch 9.0.1157: "implements" only handles one interface name Commit: https://github.com/vim/vim/commit/df8f9473596c8fb18ec893de677dba455e8925b3 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Jan 7 14:51:03 2023 +0000 patch 9.0.1157: "implements" only handles one interface name Problem: "implements" only handles one interface name. Solution: Handle a comma separated list of names. Check for duplicate names.

" Vim filetype plugin
" Language:	roff(7)
" Maintainer:	Aman Verma
" Homepage:	https://github.com/a-vrma/vim-nroff-ftplugin
" Previous Maintainer:	Chris Spiegel <cspiegel@gmail.com>
" Last Change:	2020 Nov 21

if exists("b:did_ftplugin")
  finish
endif
let b:did_ftplugin = 1

setlocal commentstring=.\\\"%s
setlocal comments=:.\\\"
setlocal sections+=Sh

let b:undo_ftplugin = 'setlocal commentstring< comments< sections<'