部分RSS源有一个GUID元素作为标识符。使用共享GUID的帖子可能会复制。部分RSS源只是把这些东西的网址在那里，表明后的独特性是依赖于它的URL。请注意，如果URL匹配，但GUID不，这可能表示，该讯息不重复。如果饲料不维护的存档，URL可能不会改变。这种情况可能是非常罕见的。

Some RSS feeds have a guid element as an identifier. Posts with a shared guid are probably duplicates. Some RSS feeds just stuff the URL in there to indicate that a post's uniqueness is tied to its url. Note that if the URL matches but the Guid does not, this may indicate that the posts are not duplicates. If a feed does not maintain an archive, the url might not change. This situation is probably pretty rare.