18:40 May 23, 2011 

It says "alta" and that is what it meand....date when it came into force...it is understood in Mexico...and you said this was on a Mexican driver´s lic. If you must really translate this without a possibility of error, you must explain whatever term you use by using an *...

17:57 May 23, 2011 

To the left of "Movimiento/Alta" is "Expedición" with a date underneath and "Vencimiento" with another date underneath five years later, so I don't think "Alta" has anything to do with "Date". "Alta" can only refer to "Movimiento".

17:40 May 23, 2011 

This is actually the action of the driving license coming into force, although Josés's suggestion of date will work. You are signed onto a system of some kind. When I take on new employees I have to "darles de alta en la seguridad social" (sign them onto National Insurance) at the same time as I register the contract, which is also "dar de alta". Cars registered are "de alta" and when they are pronounced fin de vida útil, they have to be "dados de baja"... I shan't go on...