A more thorough explanation:

Special allowance refers to a share or portion of money that is assigned or granted for a specific purpose. It can also refer to a deduction or tax break. Here are some examples:

1. Backhaul allowance: A discount given to customers who get their goods from a seller's warehouse as a reflection of the seller's freight-cost savings.
2. Family allowance: A portion of a decedent's estate set aside by statute for a surviving spouse, children, or parents, regardless of any testamentary disposition or competing claims. This support is in addition to whatever interests pass by the will or by intestate succession.
3. Depletion allowance: A tax deduction for the owners of oil, gas, mineral, or timber resources corresponding to the reduced value of the property resulting from the removal of the resource.
4. Extra allowance: An archaic term for a special sum that a court awards to the prevailing party in addition to the usual costs of court, especially in a difficult case.
5. Notice of allowance: The U.S. Patent and Trademark Office's decision to issue a patent or approve a trademark for an applicant.

These examples illustrate how special allowances can be granted for various reasons, such as to support surviving family members, incentivize certain business practices, or provide tax breaks for certain industries.