The ltra device is a general transmission line. In WRspice, this can be lossy or lossless, and is basically the same as the tra device, but defaults to a convolution approach if lossy. In other versions of SPICE, this is a lossy line that requires a model. A model property can be added to specify a transmission line model. A param property can be added to specify additional parameters.
The transmission line contains no hidden targets.