LC and other national libraries have officially adopted RDA rules for all new cataloging. Only RDA-coded authority records are permitted to be added to the LC/PCC Authority File. Similarly, all access points in bibliographic records coded “pcc” must be created under RDA rules. This applies even if the bibliographic description follows AACR2. Records with bibliographic descriptions using either AACR2 or RDA may be submitted for LTI processing, as "hybrid" records (controlled headings in RDA in records created using AACR2 rules) have been deemed acceptable for use.

There remain in the LC/PCC Authority File over 400,000 records that are identified as not suitable for RDA use. These records, flagged in a 667 field, include pre-AACR2 and AACR2 compatible records, as well as AACR2 records containing elements not compatible with RDA or that require evaluation. These headings will be upgraded over time by LC and PCC participants. Until then, LTI will continue to use the headings in their current form.

We anticipate that library transitions from AACR2 to full adoption of RDA will occur over an extended period of time. During this period LTI will assist customers in adopting the new rules for controlled headings. We also understand that some libraries have no plans or desire to implement RDA fully at this time. Those libraries may continue to create or adapt bibliographic description using AACR2 rules for their databases, while receiving the nationally approved forms of controlled headings as created under RDA rules.