All, I've got two United flights on the same day with a long stopover. The flights are on separate reservations and include checked bags because of MileagePlus status. I'm flying into Chicago for a meeting and then continuing from Chicago that evening for the rest of my trip. I have the afternoon in Chicago and would love to be able to check the roller board to my final destination rather than wheel it around town.

United tells me that since both legs are domestic, it will only check my bag to the final destination if I have than four hours between flights. The agent also said that I can't check my bag in for the 2nd flight until 4 hours prior to flight time. What is this policy I see referenced on the FT board about United checking bags through if there are fewer than 13 hours between flight segments and no overnights?