RTFD meaning in General ?

Rich Text Format Directory, also known as RTFD (due to its extension .rtfd), or Rich Text Format with Attachments, is a primary document format of TextEdit, an application native to NeXTSTEP and macOS which has also been ported to other versions of Unix. The file format is based on the Rich Text Format, but can also include "attachments" such as images and animations.

An RTFD document is a bundle, a folder containing files. It contains a Rich Text file called TXT.rtf that contains Rich Text formatting commands, as well as commands for including images or other attachments contained within the bundle. Images used in the document are stored in the bundle in their native formats.

One advantage of RTFD is that it supports scalable high quality image formats like PDF, so an RTFD file can print with no information loss at large paper sizes. The standard RTF format also supports a number of scalable image meta file formats.