Permanent Residency

I became a Permanent Resident last July. When I left the country back then I remember I had to fill out some form at Immigration at the airport. I was caught a bit by surprise since I wasn't really sure why or what I was filling out.
I will be leaving again in a couple of weeks.
Is there some requirement that I need to notify Immigration that I am leaving the country?

Thanks.

Private message sent.

Yes, you have to do paperwork in the Immigration office. If nobody's in there, the guard at the exit from Customs can call an agent. That paperwork is required to get a boarding pass.

Yes, you have to do paperwork in the Immigration office. If nobody's in there, the guard at the exit from Customs can call an agent. That paperwork is required to get a boarding pass.

Thanks
That makes sense

You will also need to retain half the document to re-enter Mexico via an airport.
But if you leave or enter Mexico by land no documentation is required - eg flying to Tijuana and walking across the airport land bridge.

I have been a Residente Permanente for over 6 years. Yes I still go to the Customs/passport office when I leave here in Queretaro and do not keep any portion of the form. I fill out the bottom, they take it and away I go. I have asked at numerous airports (DF, GDL, QRO, TIJ) and they only use that portion for tracking and statistics. It really serves no purpose. I've received my boarding pass in QRO and DF without filling out and got on planes. It depends on who is working.