All GBT scan IF FITS files should conform to the standards specified in the GBT Software Project Note 4.0, ``Device and Log FITS Files for the GBT.'' The RF signal as initially received at the antenna's receiver undergoes numerous transformations by telescope devices as it is passed from the receiver's feed to the backend's input port. The characteristics of a signal at a backend's input port is a function of the devices, device settings, and cabling along the path. The IFManager contains representations of telescope devices, accepts device settings, and reads a cabling file in order to emulate the expected terminal signal characteristics for all complete paths from a source (receiver or noise diode) to a backend port. The emulation handles changes to frequency characteristics, but not power levels. Each row in the IF FITS file represents one complete path. If the path is being altered by the sig/ref switching signal directly controlling an IF switch then the path description represents the signal position. Information in each row includes initial and terminating points in the path, polarization, nominal center frequencies, test tone characteristics (if any), Center Frequency Formual (CFF) coefficients, and a list of all devices and components affecting the signal.