To help protect your photos, you may wish to include a copyright notice in the metadata of any electronic copies of your photographs. Metadata is the information contained in the digital file of your photographs, which is visible and editable through image manipulation programs or by viewing the image properties. You can add your name, a copyright notice, your contact information, and any other information you wish to include. This serves as another way to put potential infringers on notice, and can also provide an outlet for them to purchase use rights to the photograph if they wish. In addition, metadata can serve a tracking function, proving that a certain photograph is yours. However, be aware that some image-hosting websites strip metadata from files as part of their uploading process.
Another important aspect of metadata is that if it includes information such as the name of the photographer, it may be considered copyright management information under the Digital Millennium Copyright Act (DMCA). If a copyright infringer removes this information, they can be liable for additional damages, and these damages apply even if the copyright was not registered before the infringement took place.
The International Press Telecommunications Council publishes guides on how to apply metadata and standards for what should be included.
Many modern cameras permit metadata to be added automatically in the camera settings. In addition to protecting your photos, metadata can be useful if equipment is stolen.