A more thorough explanation:

An allotment note is a legal document used in English law that allows a seaman to assign a portion of their wages to a family member, such as a wife, parent, grandparent, or sibling. This document is governed by the Merchant Shipping Act of 1970, § 13(1).

For example, if a seaman wants to support their wife financially while they are away at sea, they can sign an allotment note assigning a portion of their wages to their spouse. This ensures that their loved one receives a regular income while they are away.

Another example is if a seaman wants to support their elderly parent or grandparent who may be dependent on them financially. They can sign an allotment note assigning a portion of their wages to their family member to ensure they receive financial support.

Overall, an allotment note is a legal way for seamen to support their loved ones financially while they are away at sea.