2678 DOCX Strict OOXML Document 2007 onwards Word Processor DOCX Strict is the implementation of the Office Open XML word processor document format that strictly conforms to the ISO 29500-1: 2008-2016 standard. 301 Danish National Archives / Danish National Archives 14 Feb 2023 This format can be identified via a container signature in DROID version 6 or later. The PRONOM database cannot currently represent container signatures. 14 Feb 2023 application/vnd.openxmlformats-officedocument.wordprocessingml.document MIME fdd000400 Library of Congress Format Description Identifier fmt/1827 PUID 93 Microsoft Corporation Microsoft Corporation 93 Microsoft Corporation Microsoft Corporation docx File extension Has priority over 1160 Microsoft Word for Windows 2007 onwards