Wikimedia Commons hosts only media files such as photographs, scanned images, diagrams, animations, audio (e.g. music, spoken dialogue) and video clips, along with any associated metadata. Explanatory and other text is permitted on the file page only to the extent to which it advances Commons' aim and is not excluded educational content.
- Computer programs in any format including binary executable files and raw source code listings. Where relevant, source-code may form part of the file description or metadata, e.g. a graphics file may include as descriptive text the code used to create it.
- 仅代表原始文本的文件，例如 ASCII文件，如上所述的原始源代码清单等。
目前允许的檔案格式列表可以在Commons:Project scope/Allowable file types中找到。
Wikimedia Commons accepts only free content, in other words files that are either freely licensed or which are in the public domain. A file is considered public domain if either all copyright has expired or if the copyright owner(s) has voluntarily placed the content of the file into the public domain by irrevocably renouncing all copyright. A file which is ineligible for copyright protection is also considered public domain.
Any file hosted here must normally be freely licensed or public domain according to both the law of the United States and according to the law of the source country, if different: see Commons:许可协议.
- Restrictions on the creation of derivative works, except for copyleft.
Licences with these restrictions are allowed as long as the work is dual-licensed or multi-licensed with at least one licensing option that does not include such a restriction.
- A requirement that the copyright owner(s) be named ("attribution").
- A requirement that any derivative works must be licensed under the same terms as the original ("share-alike"/"copyleft").
Licensing policy is defined in detail at Commons:许可协议.
In the sections below, any use that is not made in good faith does not count. For example, images that are being used on a talk page just to make a point can be discounted.
A media file that is in use on one of the other projects of the Wikimedia Foundation is considered automatically to be useful for an educational purpose, as is a file in use for some operational reason such as within a template or the like. Such a file is not liable to deletion simply because it may be of poor quality: if it is in use, that is enough.
The uploading of small numbers of images (e.g. of yourself) for use on a personal user page of Commons or another project is allowed as long as that user is or was an active participant on that project.
It should be stressed that Commons does not exist to editorialise on other projects – that an image is in use on a non talk/user page is enough for it to be within scope.
An otherwise non-educational file does not acquire educational purpose solely because it is in use on a gallery page or in a category on Commons, nor solely because it is in use on a user page (the "User:" namespace), but by custom the uploading of small numbers of images (e.g. of yourself) for use on a personal Commons user page is allowed. Files relating to projects or events of the Wikimedia community, such as user meetings, are also allowed.
The emphasis here is on realistic utility, either for one of the Wikimedia projects or for some other educational use. Not all images for example are realistically useful for an educational purpose. An image does not magically become useful by virtue of the argument that it could be used to illustrate a Wikipedia article on X, merely because X happens to be the subject of the photograph.
For example, the fact that an unused blurred photograph could theoretically be used to illustrate an article on "Common mistakes in photography" does not mean that we should keep all blurred photographs. The fact that an unused snapshot of your friend could theoretically be used to illustrate an article on "Photographic portraiture" does not mean that we should keep all photographs of unknown people. The fact that an unused pornographic image could theoretically be used to illustrate an article on pornography does not mean that we should keep low quality pornographic images (see also Censorship).
Excluded from this policy are files in different formats and files which are similar but not exact duplicates in cases where they are needed to keep the file history for legal reasons.
Examples of files that are not realistically useful for an educational purpose:
- Private image collections, e.g. private party photos, photos of yourself and your friends, your collection of holiday snaps and so on. There are plenty of other projects on the Internet you can use for such a purpose, such as Flickr. Such private image collections do not become educational even if displayed as a gallery on a user page on Commons or elsewhere.
- Artwork without obvious educational use, including non-educational artwork uploaded to showcase the artist's skills
- Files apparently created and/or uploaded for the purpose of vandalism or attack. Preexisting designs and symbols that are or have been associated with nationalistic, religious or racist causes are not out of scope solely because they may cause offence. Provided they are legal to host and otherwise fall within Commons scope (e.g. if they could for example be used to illustrate a Wikipedia article on a hate group), they should be kept.
- Files that add nothing educationally distinct to the collection of images we already hold covering the same subject, especially if they are of poor or mediocre quality.
We hold many high-quality images of species-identified birds, and there is no realistic educational use for a small, blurry, poorly composed snapshot of an unidentified and unidentifiable bird. Of course, there is always room for another educationally distinct image, for example illustrating some aspect of bird behaviour that we do not currently cover, even if the image is perhaps not of the highest quality.
There may sometimes be an argument for retaining multiple images that are quite similar from an educational point of view, for the sake of variety and availability of choice, but there is no purpose in our hosting many essentially identical poor-quality images that have no realistic educational value.
New educational files of exceptional quality are always welcome, and the later uploading of such files may in principle render earlier unused poor quality files educationally redundant. However, as indicated above, a file that is used in good faith on a Wikimedia project is always considered educational, so a poor-quality file that remains in use is not liable to deletion even if a better-quality file covering the same subject later becomes available.
New and existing files of poor or mediocre quality may or may not be realistically useful for an educational purpose depending on what they illustrate and what other files we have of the same subject. Where a subject is rare and/or difficult to capture, even a poor-quality file may be of significant educational value, especially if Commons has very few or no similar files already. On the other hand, poor or mediocre files of common and easy-to-capture subjects may have no realistic educational value, especially if Commons already hosts many similar or better quality examples.
Image quality is just one of the factors that may limit the educational usefulness of a file. Other limiting factors may include low resolution and hard-to-remove watermarks.
Although PDF and DjVu file formats are permitted, they are expected to be used only in appropriate cases. There should be some reason for the choice of format that is in line with Commons' aims. All of the above rules apply as well, of course.
An admin considering whether to delete a PDF or DjVu file may have to exercise judgement as to whether the chosen format is in line with Commons' aims, and the context and intent (if known) may be relevant. For example, while a published university thesis in PDF format may be OK, a user-created original-research article that is making use of Commons as a free web-host may not be.
Files that might realistically be useful to one or more other Wikimedia projects, e.g. Wikisource or Wikibooks, should be kept; deletions should not be based on the sole ground that the file would be better hosted on one of those other projects. Any media file that is realistically useful to or is within the scope of even one other Wikimedia Foundation project can be hosted here.
Remember that Wikisource often needs PDF or DjVu files in order to proofread or create source texts: Therefore, scans of suitable editions of notable public domain works are almost always within scope for this reason. That said, remember that editorial decisions involved in preparing a text from several sources may result in a new copyright, so the editions used must be out of copyright themselves.
- The file would be within the scope of another project of the Wikimedia Foundation if it were to be uploaded in the same format to that project, for example:
- A PDF or DjVu file of a published and peer-reviewed work would be in scope on Wikisource and is therefore also in scope on Commons. Examples of in-scope documents include published books (but not vanity publishing), peer-reviewed academic papers, etc., university theses and dissertations.
- The file is a scan of a document of historic or other external significance, e.g. scans of existing copyright-free or licensed books, reports, newspapers, etc.
- The file is usable as a fixed, verifiable source document, e.g. for Wikisource or Wikibooks (appropriate fixation of content).
- The format selected provides technical advantages to at least one other Wikimedia Foundation project.
- The format has apparently been selected by the author or uploader to prevent or to discourage the creation of derivative works contrary to Commons' aims. Such inappropriate fixation of content would include a self-published vanity article or a self-created image that the author has uploaded in PDF format in an effort to discourage others from creating derivatives.
- The content is essentially raw text; such files are not considered media files. Note that scans of existing books, reports, newspapers etc of historic or other external significance are not excluded on this ground, even if they contain no images.
- The content would be prohibited under another section; for example, promotional material is outside Commons' scope regardless of the file format.
Files and other materials which are not lawful for Commons to host on its servers in Virginia will be deleted immediately upon being identified as unlawful (including copyright violations), even if the material otherwise falls within Commons scope, as set out above. However, Commons is not censored, and legitimately includes content which some users may consider objectionable or offensive. The policy of "Commons is not censored" means that a lawfully-hosted file, which falls within Commons' definitions of scope, will not be deleted solely on the grounds that it may not be "child-friendly" or that it may cause offence to you or others, for moral, personal, religious, social, or other reasons.
The counterpoint to this, is that the statement "Commons is not censored" is not a valid argument for keeping a file that falls outside Commons' defined scope, as set out above. Photographs of nudity including male and female genitalia are sometimes uploaded for non-educational motives, and such images are not exempt from the requirement to comply with the rules of Commons' scope. If the images are of demonstrably inferior quality, or add nothing educationally distinct to the stock of such images we hold already, they may fail the test of being realistically useful for an educational purpose.
A balance has to be struck between accepting useful media files with legitimate educational content that some may find offensive, and not allowing Commons to be used as a general-purpose media-hosting service (like Flickr, Photobucket, YouTube, etc.), without regard for the project's stated goals. The purpose of Commons is to serve as a media repository, a reliable resource of useful, open source media content; organized and comprehensive in coverage (with accurate file descriptions/information), educational, and intended both for use by Wikimedia projects, and as a public service freely accessible to everyone.