We have added Calendar Formats to Appendix A: Table of File Formats of NARA Bulletin 2014-04, Format Guidance for the Transfer of Permanent Records. Records in this format can now be transferred as permanent records to the National Archives. Typically, this format is used for electronic calendars.
Electronic calendars allow users or groups to create events that can be exchanged between applications or systems. The format, iCalendar or iCal (.ics), contains a variety of functions such as: events, to-do lists, journal entries, time zone, and notifications. The format can be exchanged through a range of methods including Simple Mail Transfer Protocol (SMTP), HyperText Transfer Protocol (HTTP), a file system, and protocols, like memory-based clipboard or drag and drop functions. Calendar events may include attachments in multiple file formats, such as documents or spreadsheets or other file formats. Calendar applications such as Outlook, Google, Apple, Yahoo, IBM Notes, and Groupwise support this format.
If you have questions about this, please leave a comment or email acps@nara.gov