Design Notes are notes associated with a file, but stored in a separate file. Use Design Notes to keep track of extra file information associated with your documents, such as image source-filenames and comments on file status.
You enable and disable Design Notes for a site in the Design Notes category of the Site Definition dialog box. When you enable Design Notes, you can choose to use them locally only, if you want.
If you select this option, you can share Design Notes with the rest of your team. When you put or get a file, Dreamweaver automatically puts or gets the associated Design Notes file.
If you do not select this option, Dreamweaver maintains Design Notes locally but does not upload them with your files. If you work alone on your site, deselecting this option improves performance. Design Notes will not be transferred to the remote site when you check in or put your files and you can still add and modify the Design Notes for your site locally.