There is a lot going on at TTB, so it would be easy to lose track of allergens. Way back in 2005 TTB proposed to require allergens (such as nuts and milk) to be disclosed on all alcohol beverage labels. This would follow the 2004 law change for foods more generally. The final rule is due out someday soon, according to TTB’s Agenda. In the meantime, TTB is qualifying some approvals with the following language as on the above approvals:
The disclosure of allergens used in this product is voluntary, pending final rulemaking (See Notice No. 62, 71 FR 42329). However; any reference made to allergens must declare all allergens used in the production of this product, including fining or processing agents.
For those eager to get started, the 16-page proposal is here. O’Riley’s Cream Liqueur (link above) has milk products and a detailed ingredient list. DoReMi Cream Liqueur has about the same, plus nuts.