else
let s:oneline = ' oneline'
endif
-execute 'syn region htmlItalic start="\%(^\|\s\)\zs\*\ze[^\\\*\t ]\%(\%([^*]\|\\\*\|\n\)*[^\\\*\t ]\)\?\*\_W" end="[^\\\*\t ]\zs\*\ze\_W" keepend' . s:oneline
-execute 'syn region htmlItalic start="\%(^\|\s\)\zs_\ze[^\\_\t ]" end="[^\\_\t ]\zs_\ze\_W" keepend' . s:oneline
-execute 'syn region htmlBold start="\%(^\|\s\)\*\*\ze\S" end="\S\zs\*\*" keepend' . s:oneline
-execute 'syn region htmlBold start="\%(^\|\s\)\zs__\ze\S" end="\S\zs__" keepend' . s:oneline
-execute 'syn region htmlBoldItalic start="\%(^\|\s\)\zs\*\*\*\ze\S" end="\S\zs\*\*\*" keepend' . s:oneline
-execute 'syn region htmlBoldItalic start="\%(^\|\s\)\zs___\ze\S" end="\S\zs___" keepend' . s:oneline
+syn region mkdItalic matchgroup=mkdItalic start="\%(\*\|_\)" end="\%(\*\|_\)"
+syn region mkdBold matchgroup=mkdBold start="\%(\*\*\|__\)" end="\%(\*\*\|__\)"
+syn region mkdBoldItalic matchgroup=mkdBoldItalic start="\%(\*\*\*\|___\)" end="\%(\*\*\*\|___\)"
+execute 'syn region htmlItalic matchgroup=mkdItalic start="\%(^\|\s\)\zs\*\ze[^\\\*\t ]\%(\%([^*]\|\\\*\|\n\)*[^\\\*\t ]\)\?\*\_W" end="[^\\\*\t ]\zs\*\ze\_W" keepend contains=@Spell' . s:oneline . s:concealends
+execute 'syn region htmlItalic matchgroup=mkdItalic start="\%(^\|\s\)\zs_\ze[^\\_\t ]" end="[^\\_\t ]\zs_\ze\_W" keepend contains=@Spell' . s:oneline . s:concealends
+execute 'syn region htmlBold matchgroup=mkdBold start="\%(^\|\s\)\zs\*\*\ze\S" end="\S\zs\*\*" keepend contains=@Spell' . s:oneline . s:concealends
+execute 'syn region htmlBold matchgroup=mkdBold start="\%(^\|\s\)\zs__\ze\S" end="\S\zs__" keepend contains=@Spell' . s:oneline . s:concealends
+execute 'syn region htmlBoldItalic matchgroup=mkdBoldItalic start="\%(^\|\s\)\zs\*\*\*\ze\S" end="\S\zs\*\*\*" keepend contains=@Spell' . s:oneline . s:concealends
+execute 'syn region htmlBoldItalic matchgroup=mkdBoldItalic start="\%(^\|\s\)\zs___\ze\S" end="\S\zs___" keepend contains=@Spell' . s:oneline . s:concealends
" [link](URL) | [link][id] | [link][] | ![image](URL)
syn region mkdFootnotes matchgroup=mkdDelimiter start="\[^" end="\]"
execute 'syn region mkdID matchgroup=mkdDelimiter start="\[" end="\]" contained oneline' . s:conceal
execute 'syn region mkdURL matchgroup=mkdDelimiter start="(" end=")" contained oneline' . s:conceal
-execute 'syn region mkdLink matchgroup=mkdDelimiter start="\\\@<!!\?\[" end="\n\{-,1}[^]]\{-}\zs\]\ze[[(]" contains=@mkdNonListItem,@Spell nextgroup=mkdURL,mkdID skipwhite oneline' . s:concealends
+execute 'syn region mkdLink matchgroup=mkdDelimiter start="\\\@<!!\?\[\ze[^]\n]*\n\?[^]\n]*\][[(]" end="\]" contains=@mkdNonListItem,@Spell nextgroup=mkdURL,mkdID skipwhite' . s:concealends
" Autolink without angle brackets.
" mkd inline links: protocol optional user:pass@ sub/domain .com, .co.uk, etc optional port path/querystring/hash fragment