Tokina calls this the Tokina SD 11-16mm F2.8 (IF) DX II AT-X PRO.
SD: Magic low-dispersion glass.
IF: Internal Focus.
DX: Wont work on full-frame.
II: New model of the original 11-16mm.
AT-X: Advanced Technology-seX.
PRO: Push-pull focus ring to select autofocus or manual focus.
?77: 77mm filters.
Aspherical: Specially shaped lens elements for sharper pictures.
CE: (European) Consumer Electronics safety certified.