§ 2020. Application (Rule 20)

(a) Compliance in all weathers
Rules in this Part shall be complied with in all weathers.
(b) Rules concerning lights complied with from sunset to sunrise; other lights
The Rules concerning lights shall be complied with from sunset to sunrise, and during such times no other lights shall be exhibited, except such lights as cannot be mistaken for the lights specified in these Rules or do not impair their visibility or distinctive character, or interfere with the keeping of a proper lookout.
(c) Lights during daylight hours in restricted visibility; other circumstances
The lights prescribed by these Rules shall, if carried, also be exhibited from sunrise to sunset in restricted visibility and may be exhibited in all other circumstances when it is deemed necessary.
(d) Rules concerning shapes; compliance by day
The Rules concerning shapes shall be complied with by day.
(e) Annex
The lights and shapes specified in these Rules shall comply with the provisions of Annex I of these Rules.