Contains design notes, this file format is used by various web development tools such as Dreamweaver and UltraDev.

The .MNO extension is often appended to the end of an existing extension, for example: filename.html.mno.

When a page with a recordset is created by the software, an .mno file is created in the site's _notes folder. This _notes folder is not visible in the site manager, but it can be viewed using your systems file management tool.

The MNO file contains XML information that UltraDev uses to gain information about recordsets on the page. The XML file defines the name and data type of the recordset columns. UltraDev needs this file to properly populate the data bindings panel in the design environment.