Macs and iOS devices have the benefit of not one variety of Rich Text documents, but two: RTF and RTFD.
Rich Text Format, RTF, is one of the early formats based on mark-up languages and was developed by Microsoft’s Word development team in the 1980s, being first released in Microsoft Word 3 in 1987. The current version is 1.9, which appeared over ten years ago in 2008. Unlike proper mark-up languages, it was never intended to be human-readable, and amazingly is still fundamentally based on 7-bit ASCII plain text rather than full Unicode encoding.
In the late 1980s, when the NeXTSTEP operating system was being developed for Steve Jobs’ NeXT computers, it was decided to address some of the shortcomings of RTF in a derived format, Rich Text with Attachments, or Rich Text Format Directory, RTFD… So ever since then, like two misbehaving children, RTF and RTFD have lived their own separate lives, and getting RTFD to work in Windows has been fairly futile, just as getting Apple to support richer RTF has also failed.
RTF is ideal if you need others, who won’t be using Macs or iOS devices, to be able to view or edit the document. But it’s quite limited in what it can do… If you’re confident that your document will only ever be opened on a Mac or iOS device, and particularly if you want more adventurous inclusions such as PDF, then RTFD is probably going to give you the flexibility you want.
MacDailyNews Take: Being all-Apple, we’re all-RTFD, too. Our sympathies to those who have to deal with RTF docs.
For more about what you can do with RTFD, check out Apple’s TextEdit User Guide for macOS Mojave.