Vim Scripting Cheat Sheet

if exists('g:loaded_myplugin')
  finish
endif

" ...

let g:loaded_myplugin = 1

syn match :name ":regex" :flags

syn region Comment  start="/\*"  end="\*/"
syn region String   start=+"+    end=+"+     skip=+\\"+

syn cluster :name contains=:n1,:n2,:n3...

flags:
  keepend
  oneline
  nextgroup=
  contains=
  contained

hi def link markdownH1 htmlH1

syn region inBold concealends matchgroup=bTag start="<b>" end="</b>"
hi inBold gui=bold
hi bTag guifg=blue

set conceallevel=2
syn match newLine "<br>" conceal cchar=}
hi newLine guifg=green

augroup filetypedetect
  au! BufNewFile,BufRead *.json setf javascript
augroup END

au Filetype markdown setlocal spell

hi Comment
  term=bold,underline
  gui=bold
  ctermfg=4
  guifg=#80a0ff

[nvixso](nore)map

 │       └ don't recurse
 │
 └ normal, visual, insert,
   eX mode, select, operator-pending

nmap
vmap
imap
xmap
nnoremap
vnoremap
inoremap
xnoremap
...

has("feature")  " :h feature-list
executable("python")
globpath(&rtp, "syntax/c.vim")

exists("$ENV")
exists(":command")
exists("variable")
exists("+option")
exists("g:...")