Attribution information, such as the author's name, e-mail, website, or signature, that was once visible in the image itself has been moved into the image metadata and/or image description page. This makes the image easier to reuse and more language-neutral, and makes the text easier to process and search for. Commons discourages placing visible author information in images.
This tag is placed on non-public domain licensed images, for example GFDL or CC-BY, that have had attribution, such as the author's name, e-mail, website, or signature, moved from the image to the image metadata and/or image description page, by someone other than the copyright owner. We need to track these carefully because the licenses are unclear about whether this is permitted and conservative parties such as creators of print versions may wish to avoid using this media. Here is some of the original discussion regarding this:
To add your language to the list of languages supported by this template, please copy the code of Template:Attribution metadata from licensed image/en (or any other language version you prefer to translate) and replace the text strings in there (the form below can be used to create a translation, the English version is preloaded in the edit box). Please change the parameter lang from en (or whatever language you are translating) to the language code of your language.