.MSO File Extension

File sent with Microsoft Word 2000 e-mail attachments; often named "Oledata.mso;" contains information that allows the attachment to be rendered within the e-mail message.

The Oledata.mso file will appear as a separate attachment on computers that do not have Microsoft Outlook 2000 or later installed.

File created when saving a Microsoft Office document as a Web page; contains information about macros and OLE (Object Linking and Embedding) objects included in the original file; may be referenced by the created Web page as a style sheet.

May be viewed with a text editor, but will be unreadable since the contents are encoded.