Physical Review Letters is synchronizing the online and print journals so that, beginning in January 2003, the weekly print issues will contain all papers published online in a given week. This change mirrors a similar change made to the Physical Review in August 2002. It will ensure that papers published online in a given year will appear in print in an issue dated that same year, and thus avoid ambiguity in publication date for papers published at the end of a year. To accomplish this, an additional issue, number 28, will be printed in volume 89, at the end of 2002. This issue will be mailed in January, and will contain papers published online through 31 December 2002.
In the future, print issues will be labeled by the week in which the articles are published online, with a particular week indicated by the date of the Friday of that week. For example, Letters published online in the week 25-31 January 2003 will appear in print in February in an issue labeled "Articles published week ending 31 January 2003."
Previously, paper issues were mailed within a day or two of their cover date. In the future, the mailing date will follow the cover date by approximately two weeks, although the time between online publication and print distribution will be essentially unchanged. This change reflects the fact that the online version is now considered to be definitive, while the paper version is derived from the online version. The publication date of record is the date that a paper appears in the online journal. It is shown between the byline and the abstract.