A duplicate pair is two bookmarks which take you to the same url, that is, the same web page. This generally means that they have the same url, but Bookdog digs a little deeper than that, because bookmarks with similar urls can also take you to the same web page.
Some browsers and services (Google, del.icio.us, Firefox 3 and later) do not allow duplicate pairs. If you create or import a new bookmark into one of these browsers or services which forms a duplicate pair with an existing bookmark, the existing bookmark will be immediately and silently deleted. If you create duplicate pairs in one of these documents in Bookdog, Bookdog allows you to keep them until you Save (upload) the bookmarks, then deletes them.
DetailsRegular and Feed urls. Firefox live bookmarks have a url and also a feed url. So, Bookdog considers both in making its comparison.
Canonization. Both the (regular) url and the feed url are canonized (or if you prefer, canonicalized?) to remove trivial differences which are ignored by the internet. The canonization process involves:
` # % ^ [ ] { } \ | " < >
Of course, all non-ASCII characters should also be encoded.
If a URL includes characters that should be percent-escape encoded per RFC 2396 but are not encoded, those characters are encoded. Conversely, if a URL includes characters that should not be percent-escape encoded per RFC 2396 but are encoded, those characters are decoded and replaced with the actual characters.
Comparison. Following the canonizations, Bookdog applies the following algorithm to all non-empty canonized urls: