I would agree that TSA may set the federal rules and guidelines for the minimum standard, but the carrier may set more stringent requriements. For example, I beleive Southwest Airlines state the product should be unopened, and in a leak proof container.
Southwest allows alcohol to be carried in checked luggage under the following conditions.
Alcohol (wine and liquor) must be in the original unopened container with the manufacturer's label when transported in or as checked baggage.
The maximum quantity of liquor that may be transported in or as checked baggage on Southwest Airlines is five liters per Customer. Wine is not subject to the five-liter per Customer limitation.
Alcohol content may not exceed 70% by volume (140 proof).
Alcohol (wine and liquor) in checked baggage must be securely packaged in a leak-proof bag with adequate professional packaging designed to fit the proportions of the bottle to prevent breakage.
Alcohol (wine and liquor) accepted as checked baggage must be contained within a corrugated box secured with sealing tape. The contents must be packaged in a leak-proof bag with professional packaging designed to fit the proportions of the bottle to prevent breakage.
Liquor and wine packaging is available for sale at Southwest Airlines ticket counters for $5.00 per unit.
Southwest Airlines does not accept liability for breakage of liquids or fragile items in checked luggage even if transported in special packaging purchased from Southwest Airlines.
Packaging purchased at Southwest Airlines ticket counters is intended for liquor or wine placed inside checked baggage only.
Professional packaging by alcohol and wine suppliers (e.g., cruise lines, wineries, duty-free shops) is acceptable as long as the contents have adequate cushioning and the packaging prevents leakage.
All alcohol (wine and liquor) is subject to TSA screening.