A post that is the same or inferior to an already existing post. This tag only applies to inferior posts that were uploaded after an already existing identical post.
Duplicates should not be confused for the following:
image sample, an image typically used by sites to load images faster.
md5 mismatch, an post that has a different md5 from the file at the source.
revision, a post that has been revised by the artist from a previous version.
variant set, posts with a similar base, but non-trivial differences.
scan, a post that has been scanned from another source.
Resized posts. Note that duplicate resized posts should not be tagged with md5 mismatch.
Images of generally lower quality; often a result of jpeg artifacts.
Before you upload something, check if it has already been uploaded by using the IQDB image search or the "Find similar" button.
Most duplicates are tagged manually; only pixel-perfect duplicates are tagged automatically. There is no automated system in place to accurately tag non pixel-perfect duplicates given how easy it is to confuse them for the above (with the exception image samples where the original is already uploaded).
Notes:
Do not flag a duplicate post for deletion if your only reason is that the post is a duplicate.
