For the calculation of unbraced length of beams and C-Beam™, both the top and bottom flanges are considered to be braced wherever another beam or C-Beam frames in. For C-Beam members this is true regardless of the type of c-beam-to-beam connection designated in the Criteria > C-Beam command. Note that this assumption is made even when Bearing connections are designated, which in reality do not brace the bottom flange. This assumption has no impact on the supporting beam if the beam has no negative moment (i.e., it is not in uplift), but may be unconservative when the supporting beam has a negative moment (i.e., it is in uplift, resulting in compression on the bottom flange).