Just popping in and saw that your husband got his military conscription registration document. Congratulations, LeisaP.
I realize that you may not be familiar with the intricacies of Mexico and that is perfectly understandable since you're visiting and haven't spent much time there. I think it's really cool that you're trying to learn and embrace the culture and for that I commend you.
In that spirit, let me share a bit about the 'pre-cartilla' to clear up some misunderstandings. Every male who grows up in Mexico knows from a very early age that when they turn 18 they need to register for military service - it is culturally engrained. The only exception may be males who are in Indian tribes in really remote regions of the country who still communicate in Nahuatl or other ancient dialects (think First Nation in really remote, hard-to-access regions). Anyone who is in mainstream Mexican society - from the richest of the rich to the poorest of the poor - is aware of this rite of passage (in the same way that any Canadian past a very young age knows you need a driver's licence to drive a car and nervously looks forward to that rite of passage the closer it gets). As you are aware from others, you need the 'pre-cartilla' for the PGR. But, it isn't only for the PGR that your husband needs it ... the Canadian Embassy in Mexico has been known to ask for a 'pre-cartilla liberada' indicating that the citizen has completed his military service before issuing a CoPR, as edgarsitow mentioned earlier, employers usually ask for it in order to give you a job (given that otherwise if you haven't completed military service, the employer faces stiff penalties), and the government isn't supposed to provide you with any services unless you have registered and completed your obligation. You can register either where you live in Mexico or at a Mexican Embassy or Consulate abroad. If you live in Mexico, most people register and then go to the ball-lottery. Folks with black balls are done, whereas those with white or blue balls go to training for half a day on Saturdays for a year (8am to 1pm). If you live abroad when you register, you automatically get an exemption and the 'pre-cartilla liberada' without needing to go through the whole ball-routine and possibly military service.
I understand that this may all seem foreign to you since Canada hasn't had conscription since WWII. Many countries around the globe have conscription. In the US, males need to register with the Selective Service when they reach 18 and advise the Selective Service every time they move until they reach 26.
So, I think you should congratulate your other-half on successfully obtaining the pre-cartilla today. It's the best possible outcome you could have. If you read the law, the outcome could have been very, very different (including jail time). Be happy the ladies were just 'grumpy' and that they didn't turn him in for breaking the law. You are the lucky ones today.
When you have a moment, run the law through Google Translate or some other translation software (http://www.sedena.gob.mx/images/stories/archivos/leyes_y_reglamentos/leyes/LEY_DEL_SERVICIO_MILITAR.pdf) to learn all the details.
