I think '20XX' would represent some unknown year in the 21st century, rather than the 21st century as such. This is a distinction that is often overlooked. I don't think there is any difference in functionality between '20uu' in the old specification and '20XX' in the new. If we say someone was born in the 21st century, '20XX' would apply. If we say someone was active in the 21st century, then we are referring to the century (sort of). Then the unsatisfactory ISO 8601 technique of using '20' might be applicable. John ------------------------------------------ John Hostage Senior Continuing Resources Cataloger Harvard Library--Information and Technical Services Langdell Hall 194 Harvard Law School Library Cambridge, MA 02138 [log in to unmask]<mailto:[log in to unmask]> +(1)(617) 495-3974 (voice) +(1)(617) 496-4409 (fax) ISNI 0000 0000 4028 0917 From: Program for Cooperative Cataloging [mailto:[log in to unmask]] On Behalf Of Robert Maxwell Sent: Monday, October 22, 2018 17:20 To: [log in to unmask] Subject: Re: [PCCLIST] Revised EDTF Also it looks as though we can now express a century using EDTF: Unspecified digit(s) from the right The character 'X' may be used in place of one or more rightmost digits to indicate that the value of that digit is unspecified, for the following cases: 1. A year with one or two (rightmost) unspecified digits in a year-only expression (year precision) Example 1 '201X' Example 2 '20XX' I assume 20XX = 21st century, correct? If so, we can now code everything using EDTF, e.g. 046 20XX $2 edtf Should we begin using this coding, even though LC-PCC PS 9.3.1.3 says not to? I think the LC-PCC PS was so written because the EDTF draft at the time did not include the ability to express a century. Bob Robert L. Maxwell Ancient Languages and Special Collections Librarian 6728 Harold B. Lee Library Brigham Young University Provo, UT 84602 (801)422-5568 From: Program for Cooperative Cataloging <[log in to unmask]<mailto:[log in to unmask]>> On Behalf Of Adam L. Schiff Sent: Monday, October 22, 2018 3:09 PM To: [log in to unmask]<mailto:[log in to unmask]> Subject: Re: Revised EDTF Among the changes, it appears that codes such as 196u are no longer valid EDTF. Will there be any effort for cleaning up invalid/obsolete codes in authority records? Adam From: Program for Cooperative Cataloging [mailto:[log in to unmask]] On Behalf Of Hostage, John Sent: Monday, October 22, 2018 2:00 PM To: [log in to unmask]<mailto:[log in to unmask]> Subject: FW: Revised EDTF From: Discussion of the Developing Date/Time Standards [mailto:[log in to unmask]] On Behalf Of Denenberg, Ray Sent: Monday, October 22, 2018 15:40 To: [log in to unmask]<mailto:[log in to unmask]> Subject: Revised EDTF The new version of ISO 8601 is being prepared for final ballot and is now expected to be published in mid-2019. There will be two parts. Part 1 is essentially the same as 8601-2004 (with some corrections). Part 2 is extensions. There are many extension, including EDTF functionality (some syntactic changes were necessary, to satisfy international requirements), and in addition, EDTF is included as an ISO 8601 profile. The draft specification from 2012 has therefore been superseded and a revised EDTF Specification<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.loc.gov_standards_datetime_edtf.html&d=DwMFAw&c=WO-RGvefibhHBZq3fL85hQ&r=O9-UIVab7e9YxpBphmOmeEQruoCpRWXNPKDBg9tfb88&m=p5rbRNn9YwcJU42i1RrRSpeuztt_6aWrzU2IoiMSjZ4&s=0qXGaNCDD1IAMF2fe-svkz5oGfLZVBKz_9SRjc-xlNk&e=> based on the revised 8601 is now available. Ray