I’ve twice encountered what appears to be an intermittent bug in Word 2007. When I submit articles for publication, I usually choose RTF format, because it is universally readable. It is not perfect for exchanging formatted documents, since there are many variations of RTF and new tags appear with each new version of Word, but for simple formatting in everyday documents it is fine. That said, with Word 2007 I’ve had some problems. I’ve exported as RTF in the normal way, but later had an email to say that they do not open. On investigation, I’ve found that although the document has an RTF extension, it is actually .docx, a part of Office Open XML and the default format of Word 2007.

How can you tell? Docx is an XML format, but it is also zipped, so if you try opening it as plain text it is mostly unreadable. However, it appears that the path names are left intact. If you open a file that begins PK and contains bits of text like:

word/_rels/document.xml.rels

then the chances are that it is docx.

None of this is particularly obvious to the recipient of the supposed RTF file. But what makes me think this is a bug in Word, as opposed to my own mis-click? Well, it is difficult to do by accident. If you open Word’s Save As dialog, which is what I normally do, name your document something.rtf, but forget to change the document type, you actually get a document called something.rtf.docx. In order to get a .docx with an .rtf extension, you have to type quote marks around the name, not something you would do unawares. To make matters worse, Word itself will actually open these wrongly typed documents without protest. It is only a recipient without Word 2007 that has a problem. A shame, because receiving an unreadable document can be very inconvenient. Let me emphasize: saving as RTF usually works fine. Just once in a while I get this unfortunate mix-up.