Most warrants of this type are issued to grant a rank to a member of the nobility or gentry that they would normally have enjoyed when their relative (usually their sibling) inherits a title, but failed to assume automatically due to such circumstances as the death of their father (see courtesy title).
These warrants are typically issued to grant a rank to members of the nobility or gentry who would have inherited a title if their relative (typically a sibling) had taken up that title upon inheriting it, but did not because of factors like the death of their father (see courtesy title).