In some old apps with fbml I used fb:name to get the name of the user on the tab page, even if he did not accept the app. Is there any replacement for this tag?
thanks so much
no, there is not. FBML has been deprecated.
From the Facebook dvelopers roadmap :
FBML will no longer be supported as of January 1, 2012. Aside from security and privacy related bugs, we will not fix any bugs related to FBML after January 1, 2012. On June 1, 2012 FBML endpoints will be removed from Platform
You need to have required permissions in order to do that. Use graph API to query details of the user.
Use XFBML. fb:name does also exist in XFBML.