General form:

OXXXXXXX n1 n2 n3 n4 mname

Examples:

O23 1 0 2 0 LOSSYMOD
OCONNECT 10 5 20 5 INTERCONNECT

This is a two-port convolution model for single conductor lossy transmission lines. n1 and n2 are the nodes at port 1; n3 and n4 are the nodes at port 2. Note that a lossy transmission line with zero loss may be more accurate than the lossless transmission line due to implementation details.