When you're using a version of Word that's newer than the version used to create your document, you typically see Compatibility Mode in the title bar. Compatibility Mode temporarily disables new or enhanced Word features so that the document can still be edited by people using the earlier version of Word. Compatibility Mode also preserves the layout of the document.
Converting the document to the newer format lets you use newer features, but conversion might create difficulties for people who are using earlier versions of Word to edit the document. If you convert the document, they might not be able to work with certain portions of the document that were created in the newer versions of Word.
Find which Compatibility Mode you are inWhen you open a document in Word 2016 that was created in Word 2007 or Word 2010, you see Compatibility Mode in the title bar of the document window. If you open a Word 2013 document in Word 2016, you don't see Compatibility Mode because Word 2013 and Word 2016 are already compatible.
When you open a document in Word 2016, it’s in one of these modes:
If you see Compatibility Mode in the title bar, here's how you can find out which mode you're in:
You can either work in Compatibility Mode or you can convert your document to the Word 2016 file format. The Word Convert command clears the compatibility options so that the document layout appears as it would if it had been created in Word 2016 .