I don't find the info now, but I have read/hear a re-entry permit is only valid for 6 months. So, if you stay abroad longer, your 13A is void and you have to re-apply.
I have also heard 13A holders coming back after longer than 6 months. But, as always, it depends on the mood of the immigration officer. If you break a rule, you are f*cked if they are on that mood.
[DOUBLEPOST=1430993116,1430992908][/DOUBLEPOST]Found it. I was partially right. It's for 12 months. Not 6.
Request Rejected
[DOUBLEPOST=1430993283][/DOUBLEPOST]The re-entry permit is included in the 2170p you pay when you leave, and registered on your ACR-I card.
Since the I-Card there is no need to get the old Green/Blue hard card with re-entry stamp in.
BUT, if you need to go abroad while they renew your ACR-I card, you have to go to the immigration and secure the old style re-entry permit.