1. A computer implemented method of performing incremental coupling, comprising: using at least one processor that is configured or programmed for performing a process, the process comprising: providing a cross-reference node situated at a known location and including reference between a net and at least one of one or more neighboring nets, the cross-reference node relating to cross-coupling between the net and the at least one of the one or more neighboring nets; determining a first constraint level for the cross-reference node, wherein the first constraint level corresponds to permitted actions for the cross-reference node in an event of a modification to the one or more neighboring nets; identifying the modification to a specific neighboring net; and applying the permitted actions for the cross-reference node based at least in part upon the specific neighboring net while preserving the cross-reference node at the known location regardless of changes that occur to the net or to the at least one of the one or more neighboring nets.