According to the European and American law, no copyright applies to any of the images of charts stored in this database, since their authors have died more than 75 years ago, and the digital reproductions hosted by the system are meant to be no more than exact photographic copies of the originals. Thus, all reproductions fall into the copyright category of ‘public domain’, which means that they can be used discretionarily by any individual or organization.

However, the libraries and archives where the originals are kept maintain the right to charge a fee for digital copies and/or to make an agreement with buyers limiting or preventing the dissemination of images. This is the case for some highest resolution reproductions in the database, which were purchased by the MEDEA-CHART project on the condition that they should not be distributed. In these instances, only lower resolution versions are accessible to the general user.

Notes on credits to authors and archives

• Respect authorship. Make sure that proper credits are made to the original creators of the charts and atlases when digital reproductions of their works are used elsewhere. Adaptations made to an image should not be attributed to the original creator.
• Credit the source. Cite the library or archive that holds the originals, as well as their shelf-marks. Whenever possible, provide a link to the images on the library or archive's website. When such a link is unknown, provide a link to the MEDEA-CHART database entry.
• Support the public domain. When using images downloaded from the database, please try to keep them under public domain and free of charge.