In many cases, the tag list becomes very long and contains heterogeneous tags. It should be better to group them: this feature is implemented in the Lepagito theme. For instance, in the pelicanconf.py file:

TAGS_BY_GROUPS = (
  ('Color',  ('blue', 'red', 'yellow')),
  ('State',  ('solid', 'liquid', 'gas')),
  ('Firtname', ('Isabelle', 'Pierre', 'Paul', 'Jacques')),)

If a tag appears in an article but has any defined group, it will appear in the 'Others' group.