docs: def filter_label(label, replace_by_similar=True):
      """Some labels currently don't work together because of LaTeX naming
         clashes. Those will be replaced by simple strings. """
      bad_names = ['celsius', 'degree', 'ohm', 'venus', 'mars', 'astrosun',
                   'fullmoon', 'leftmoon', 'female', 'male', 'checked',
                   'diameter', 'sun', 'Bowtie', 'sqrt',
                   'cong', 'copyright', 'dag', 'parr', 'notin', 'dotsc',
                   'mathds', 'mathfrak']
      if any(label[1:].startswith(bad) for bad in bad_names):
          if label == '\\dag' and replace_by_similar:
              return '\\dagger'
          elif label == '\\diameter' and replace_by_similar:
              return '\\O'
          return label[1:]
      else:
          return label