WASHINGTON — President-elect Donald Trump has expressed frustration that flags will be flying at half-staff when he takes office later this month. ...On Dec. 29, Biden ordered that U.S. flags be flown at half-staff in honor of the late former president. It's an honor that indicates that the country or a state is in mourning. The U.S. flag code lays out parameters for lowering the U.S. flag to half-staff, including a 30-day period for current or former presidents to cover flags at federal government buildings and their grounds, as well as at U.S. embassies and other facilities abroad, including military...