Wonderful! thxs Vincent!

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- For all pages with breadcrumb modified, I must convert manually terminale "parent"page in none terminale page ? - how can I retrieve these pages with breadcrumb modified ?

http://platform.xwiki.org/xwiki/bin/view/Features/ContentOrganization/Nested...

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- when I upgrade xwiki the old breadcrumb information is lost (overwrited by new one)?

http://platform.xwiki.org/xwiki/bin/view/Features/ContentOrganization/Nested... "We've hidden the parent-child feature Even though it's hidden you can still turn it back on if you need it while you migrate your content to use Nested Spaces: set the core.hierarchyMode property to parentchild in the xwiki.properties configuration file."

See http://platform.xwiki.org/xwiki/bin/view/Features/ContentOrganization/

And in that page the section: http://platform.xwiki.org/xwiki/bin/view/Features/ContentOrganization/#HMigr...