This attribute when set to 'true' indicates that the CMTS forces UCC messages instead of DCC messages in those scenarios that are allowed as defined in the Upstream Channel Change Request (UCC-REQ) section of MULPI. In some cases the CMTS may still use UCC commands even though this attribute value is 'false', for example in an upstream-only change-over operation directed to a CM that the CMTS is aware is only capable of UCC, but the operator is not aware of the CM capabilities. This attribute value is ignored when the target CM for the change-over operation is in MRC mode, or the UsChSet attribute is the zero-length string, or the operation includes changes for downstream channels.