The Rule: When a vessel is in distress and requires assistance, she shall use or exhibit the signals described in Annex IV to these Rules.

Discussion: This rule is best memorized using the provided picture of 16 distress signals. Annex IV simply lists these methods out in written form. 

Test Strategy: These 16 distress methods must be memorized for the exam, or you should at least be familiar with what they are until you are able to answer rule 37 questions accurately.