message: Convert #i into argi
  The character '#' is used as a comment sign in .cwl files, except when
  in the form #[0-9] in caption.cwl
diff: @@ -48,6 +48,9 @@ class PlaceHolder:
  else:
  return '${' + str(self.count) + name + '}'
  +def apply_caption_tweaks(content: List[str]) -> List[str]:
  + return [re.sub(r'#([0-9])', r'arg\1', line, flags=re.A) for line in content]
  +
  def get_unimathsymbols_file():
  if not exists('unimathsymbols.txt'):
  @@ -134,6 +137,8 @@ def parse_cwl_file(
  lines = f.readlines()
  pkgcmds: Dict[str, Dict[str, str]] = {}
  pkgenvs: Dict[str, Dict[str, str, str]] = {}
  + if file == 'caption.cwl':
  + lines = apply_caption_tweaks(lines)
  for line in lines:
  line = line.rstrip()
  index_hash = line.find('#')
  