The n+ and n- are the positive and negative nodes, respectively. The parameter modname is the model name, area specifies the area factor, temp specifies the operating temperature, and off indicates an (optional) starting condition of the device for dc analysis. If the area factor is omitted, a value of 1.0 is assumed. The (optional) initial voltage specification using ic=vd is intended for use with the uic option in transient analysis, when a transient analysis is desired starting from other than the quiescent operating point. The .ic line provides another way to set transient initial conditions.
See the description of the diode model in 2.17.7 for more information.