vim/runtime/syntax/testdir/input/vim_ex_syntax.vim

" Vim :syntax command

syn match testMatch "pattern" contained " tail comment
" NOTE: comments not currently supported
syn keyword testKeyword keyword contained " tail comment
syn region testRegion start="start-pattern" skip="skip-pattern" end="end-pattern" contained " tail comment

" Multiline commands

syn keyword testKeyword
      "\ OPTIONS
      "\ conceal option
      \ conceal
      "\ cchar option
      \ cchar=&
      "\ contained option
      \ contained
      "\ containedin option
      \ containedin=testContainer
      "\ nextgroup option
      \ nextgroup=testNext0,@testCluster
      "\ transparent option
      \ transparent
      "\ skipwhite option
      \ skipwhite
      "\ skipempty option
      \ skipempty
      "\ skipnl option
      \ skipnl
      "\ KEYWORDS LIST
      "\ keyword 1
      \ keyword1
      "\ keyword 2
      \ keyword2
      "\ keyword 3
      \ keyword3

syn match testMatch
      "\ MATCH PATTERN
      "\ pattern start
      \ /
      "\ part 1 description
      \pat1a .* pat1b
      "\ part 2 description
      \pat2a .* pat2b
      "\ part 3 description
      \pat3a .* pat3b
      "\ pattern end
      \/
      "\ OPTIONS
      "\ conceal option
      \ conceal
      "\ cchar option
      \ cchar=&
      "\ contained option
      \ contained
      "\ containedin option
      \ containedin=testContainer
      "\ nextgroup option
      \ nextgroup=testNext0,@testCluster
      "\ transparent option
      \ transparent
      "\ skipwhite option
      \ skipwhite
      "\ skipempty option
      \ skipempty
      "\ skipnl option
      \ skipnl
      "\ contains option
      \ contains=testContained1,testContained2
      "\ fold option
      \ fold
      "\ display option
      \ display
      "\ extend option
      \ extend
      "\ excludenl option
      \ excludenl
      "\ keepend option
      \ keepend

syn region testRegion
      "\ OPTIONS
      "\ start option
      \ start="start-pattern"
      "\ skip option
      \ skip="skip-pattern"
      "\ end option
      \ end="end-pattern"
      "\ conceal option
      \ conceal
      "\ cchar option
      \ cchar=&
      "\ contained option
      \ contained
      "\ containedin option
      \ containedin=testContainer
      "\ nextgroup option
      \ nextgroup=testNext0,@testCluster
      "\ transparent option
      \ transparent
      "\ skipwhite option
      \ skipwhite
      "\ skipempty option
      \ skipempty
      "\ skipnl option
      \ skipnl
      "\ contains option
      \ contains=testContained1,testContained2
      "\ oneline option
      \ oneline
      "\ fold option
      \ fold
      "\ display option
      \ display
      "\ extend option
      \ extend
      "\ concealends option
      \ concealends
      "\ excludenl option
      \ excludenl
      "\ keepend option
      \ keepend

syn cluster testCluster
      "\ OPTIONS
      "\ contains option
      \ contains=testContained1,testContained2,testContained3

syn cluster testCluster
      "\ OPTIONS
      "\ add option
      \ add=testAdd
      "\ remove option
      \ remove=testRemove


" multiline group list

syn keyword testNext0 keyword
syn keyword testNext1 keyword
syn keyword testNext2 keyword
syn keyword testNext3 keyword
syn keyword testNext4 keyword
syn keyword testNext5 keyword
syn keyword testNext6 keyword
syn keyword testNext7 keyword
syn keyword testNext8 keyword
syn keyword testNext9 keyword

syn keyword testKeyword
      "\ nextgroup option
      \ nextgroup=
      "\ a comment
      \ testNext0 , testNext1 , 
      "\ a comment
      \ testNext[2-8].* , 
      "\ a comment
      \ testNext9 , @testCluster skipwhite
      "\ KEYWORDS LIST
      \ keyword4
      \ keyword5
      \ keyword6


" leaking contained groups

" Example: runtime/syntax/zsh.vim
"   "cluster" should not be highlighted outside of :syntax commands

function! s:ContainedGroup()
  " ...
  for cluster in ['markdownHighlight_zsh', 'zsh']
    " ...
  endfor
  " ...
endfunction