Many of our scripts have copyright notices at the top like this (category.py):
# (C) Rob W.W. Hooft, 2004
and then:
# (C) Pywikibot team, 2008-2013
even if most contributors (e.g. Rob W.W. Hooft) are regularly listed in CREDITS.

Is it to mark the main contributors? I haven't seen that notices being updated for months, even when some scripts get significantly improved or rewritten.