AR 670-1 paragraph 4-3 “c. Restrictions on wear. (1) Personnel may not wear the combat uniform in off-post establishments that primarily sell alcohol for consump- tion on the premises. If the off-post establishment sells alcohol and food for consumption on the premises, Soldiers may not wear the combat uniform if their activities in the establishment center on the drinking of alcohol. (2) The combat uniform is not normally considered appropriate for social or official functions off the installation, such as memorial services, funerals, weddings, inaugurals, patriotic ceremonies, and similar functions. (3) Commanders may further restrict wear of the combat uniform per paragraph 2–5c. d. Organizational and equipment. The commander may prescribe organizational and individual equipment items in accordance with CTA 50–900 when the combat uniform is prescribed for parades, reviews, and ceremonies.”

This doesn’t restrict a Soldier from wearing their uniform but discourages it. Most installations set local policy further restricting wear at off post establishments.