(d) The choice-of-law rule for the interpretation of a registered order is that the law of the issuing State governs the underlying terms of the controlling support order. One important exception exists; if the registering and issuing State have different statutes of limitation for enforcement, the longer time limit applies, Section 604.

3. CONTINUING EXCLUSIVE JURISDICTION AND THE ONE-ORDER SYSTEM. Under URESA and RURESA the majority of support proceedings were de novo. Even when an existing order of one State was "registered" in a second State, the registering State often asserted the right to modify the registered order. This meant that multiple support orders could be in effect in several states. As far as is possible, under UIFSA the principle of continuing, exclusive jurisdiction aims to recognize that only one valid support order may be effective at any one time, Sections 205-207. This principle is carried out in Sections 203-211.

4. PRIVATE ATTORNEYS. UIFSA explicitly authorizes parties to retain private legal counsel in support proceedings, Section 309, as well as to use the services of a state support enforcement agency, Section 307(a). The Act expressly takes no position on whether the support enforcement agency's assistance of a supported family establishes an attorney- client relationship with the applicant, Section 307(c).

5. EFFICIENCY. UIFSA streamlines interstate proceedings as follows:

(a) Proceedings may be initiated by or referred to administrative agencies rather than to courts in those states that use those agencies to establish support orders, Section 101(22).

(b) Under the old system, the process began by requiring a local "initiating tribunal" to make a preliminary (and nonbinding) determination of a duty to support, and then forwarding the documents to a "responding tribunal" for a binding decision. Under UIFSA an individual party or support enforcement agency in the initiating State may file a proceeding directly in a tribunal in the responding State, Section 301. This innovation by UIFSA has proven to be a major contribution to efficient case management. In the unlikely event that some local action is needed, initiation of an interstate case in the initiating State is expressly made ministerial rather than a matter for adjudication or review by a tribunal.