This obsolete read-create value selected whether data transmitted on the FT1 interface was sent normal or inverted, defaulting to normal. An admin would set this to inverted for certain line coding configurations to guarantee sufficient one's density so the remote end's clock recovery circuitry could stay synchronized; the object was later obsoleted in this MIB. For example, on an older FT1 link using AMI line coding with sparse data patterns, setting rsFt1IfDataPolarity to inverted(1) helped the far-end equipment maintain timing lock.