Send DOCX. It is an international open standard, it is what editors work in, and it carries the full modern markup an editorial pass depends on.
RTF is not broken and it is not incapable, which is where most advice on this question goes wrong. It is frozen. Microsoft stopped developing it in 2008, and anything Word has added since is lost when a file is saved to it.
The Claim You Will See Everywhere, and Why It Is Wrong
The standard argument against RTF is that it cannot carry tracked changes or comments. That is simply false, and it is worth correcting because a wrong reason is a fragile reason.
Microsoft's own RTF specification has dedicated sections titled "Track Changes (Revision Marks)" and "Comments (Annotations)", with documented control words for each: \revtbl, \revised, \revauth, \revdttm for revisions, and \annotation, \atnid, \atnref, \atnauthor for comments. The Library of Congress confirms it in its own words, recording that RTF "can store information associated with the process of creating and reviewing documents, including tracked changes and other annotations".
So an editor could mark up an RTF file. The question is what happens to that markup.
The Real Argument: Frozen in 2008
The Library of Congress format description for RTF is unambiguous:
"Version 1.9.1 was published in March 2008 and is the last release, compatible with Word 2007."
"Since 2008, the RTF specification has been frozen. Hence, for all versions of Word later than Word 2007, RTF files saved from Word are vulnerable to information loss."
Microsoft says the same thing in its own voice. Its Word 2010 change documentation states:
"The RTF file format is no longer enhanced to include new features and functionality. Features and functionality that are new to Word 2010 and future versions of Word are lost when they are saved in RTF."
Note what that statement is and is not. Microsoft never announced that RTF was deprecated or retired, whatever year you have seen asserted for it. What Microsoft said is that the format stopped being developed and that newer features do not survive a save. That is the accurate claim, and it is damaging enough on its own.
The practical consequence for an editorial workflow: RTF represents Word 2007's idea of a comment. Modern threaded and resolvable comments, which are how an editor and an author actually hold a conversation in the margin, are outside its feature set. The Library of Congress notes this asymmetry precisely, listing "threaded comments" in its DOCX description and not in its RTF one.
Three More Reasons, All Sourced
Standardisation. DOCX is an "International open standard. Maintained by ISO/IEC JTC1 SC34/WG4", approved as ISO/IEC 29500 in 2008. RTF is "a proprietary format developed by Microsoft", and Microsoft "has not kept an archive of past versions". One of these is a specification anybody can implement against. The other is a frozen artefact whose own vendor did not keep the history.
Character encoding. RTF "does not use a UTF encoding". For a manuscript containing accented names, curly quotes, dashes or any non-Latin text, that is a live corruption risk rather than a theoretical one.
Accessibility. Section 508 guidance, quoted by the Library of Congress, advises saving as .docx "to preserve accessibility features", noting that RTF, DOC, TXT and ODF "may not be accessible". The Library of Congress adds that RTF cannot carry alt text for images, while DOCX "files have good support for accessibility features".
There is also a security point worth retiring the opposite folklore over. RTF is sometimes recommended as the safe format because it supposedly cannot carry macros. The Library of Congress documents RTF-borne exploits and two Microsoft security bulletins, MS14-017 and MS15-033, arising from the ability to embed binary objects in RTF files.
In preservation terms both formats are acceptable to the Library of Congress, but they are not equal. DOCX sits with the XML-based document formats. RTF sits at the bottom of the acceptable column in a residual "other formats" bucket, and the Library of Congress states the ranking outright, listing RTF as acceptable "but with low priority compared with XML-based formats and PDF/A".
What Editorial Bodies Actually Say
Here is the genuine surprise. No professional editorial body names a file format. What they specify is the markup method, agreed in advance.
Editors Canada's Professional Editorial Standards put it as a standard:
"When working on screen, use an agreed-on system for tracking and showing edits (e.g., Track Changes, PDF markup tools)."
The CIEP's editorial brief template has a row headed "File format and markup", asking which medium the work should be done in and "How you want the editorial professional to display their edits". Its client-facing briefing checklist covers enclosures, depth of edit, house style, fees and schedule, and never specifies a format at all.
Two things follow. First, the format question is downstream of the markup question, so ask your editor what they want before assuming. Second, "never send a PDF" is wrong as a blanket rule, because both Editors Canada and the CIEP name PDF markup as a legitimate method. The narrower true claim is that PDF is unsuitable for a copyedit that has to be made into the manuscript file, since the editor cannot hand you back an edited manuscript, only an annotated picture of one.
Where publishers do state a format, DOCX is on the list and RTF is not. Yale University Press asks authors to "send it as a Word or PDF attachment (10 mb or less)".
Is There Any Reason Left to Send RTF?
One, and it is not really about you: a collaborator running software genuinely too old or too niche to open DOCX. That is a workaround for their constraint, not a best practice, and it is rare now that free and web-based editors all handle DOCX.
The historical case for RTF was cross-platform interchange. DOCX does that job at least as well today, and the Library of Congress cautions that RTF support "may vary, depending on which chronological version of RTF the support is based on", which "may not be obvious from product documentation". A format whose compatibility you cannot verify is not an interchange format.
What Deckle Exports
Deckle exports DOCX, EPUB and PDF, plus Markdown and plain text on a separate path. There is no RTF export, and on this evidence there is no reason to want one.
The DOCX export matters more than the format label. Choosing the Word variant produces a document built from real Word paragraph styles, Body Text, First Paragraph, Heading1, Heading2, Scene Break and the block styles, rather than direct formatting. That is what lets an editor restyle or restructure the whole manuscript in one action instead of paragraph by paragraph, and it is the practical difference between a file an editor can work in and one they have to repair first.
If you are sending to an agent rather than an editor, turn on Standard Manuscript Format as well, which adds the submission title page and running header described in what is standard manuscript format. If you are sending to a typesetter rather than an editor, the InDesign variant is the right choice, covered in handing off to a professional typesetter.
For the wider question of which format goes where, see EPUB vs PDF vs DOCX for publishing, and for moving work between applications, how to move a manuscript between writing apps. For readers rather than editors, see how to send a manuscript to a beta reader.
Common Mistakes
- Believing RTF cannot do tracked changes. It can. It is frozen at Word 2007, which is the real problem.
- Saying Microsoft deprecated RTF. Microsoft said it is no longer enhanced. That is the sourced claim.
- Choosing RTF for safety. It has a documented exploit history and no UTF encoding.
- Assuming PDF is always wrong. Two editorial bodies name PDF markup as legitimate. It is wrong for a copyedit specifically.
- Sending direct formatting instead of styles. The format is only half of what makes a file workable.
- Not asking first. Every body's actual guidance is to agree the markup method in advance.
FAQ
Q: My editor asked for RTF. Should I argue? A: No. Send what they ask for. They know their tools, and it is their workflow.
Q: Can an editor track changes in an RTF file? A: Yes. The format supports revision marks and comments. It just cannot represent anything Word added after 2007.
Q: Is .doc as bad as RTF? A: It is the older binary Word format, superseded by DOCX. Use DOCX unless asked otherwise.
Q: What about ODT? A: An ISO standard and technically fine, but most editors work in Word, so DOCX removes a conversion step.
Q: Should I send a PDF instead so nothing shifts? A: Only for a proofread of final pages. An editor cannot edit a PDF back into your manuscript.