What is "pan-alcidae"

Pan-Alcidae is a clade of charadriiform birds containing the auks and their extinct relatives. It was named in 2011 by N.A. Smith, who defined it as all descendants of the common ancestor of the group Mancallinae and crown group auks (Alcidae), but some have disputed the use of the Pan- prefix in general for family-group names regulated by the Zoocode (ICZN Code).