RTFD

A Rich Text Format Directory is a MacOS Bundle which is a directory containing an RTF and other attachments such as images or animations.^[1] In the MacOS the directory acts as a single file and can be created or viewed with Textedit.^[2][3] Developed in the 1980's for the NeXTSTEP system.^[4]

References

1. ↑ https://en.wikipedia.org/wiki/Rich_Text_Format_Directory
2. ↑ https://eshop.macsales.com/blog/62110-textedits-hidden-talents/
3. ↑ https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/AttributedStrings/Tasks/RTFAndAttrStrings.htm
4. ↑ https://eclecticlight.co/2019/07/30/rich-text-documents-rtf-and-rtfd/