CAS source document coverage practice had been to cover the original language editions of all journals and to ignore any translation journals. This practice had been followed because of the often incomplete nature and poor currency of the translation editions. However, it had become apparent in recent years that some of the translation journals were now published at the same time as the original foreign-language editions and contained the complete contents of the original editions. Because of this, and because the English-language editions are often more widely distributed and archived than the foreign-language editions, CAS decided to begin to selectively switch its coverage to the English-language editions when CAS was confident that there would be no loss in comprehensiveness and timeliness.