@Erik **********
There are TWO white slips from Immigration in my passport. ONE is the 90-days report slip with the date when the next 90-days report is due. And THE OTHER is the TM30 receipt. When you exit Thailand, normally at the border both slips are removed . . since there now are automated gates, the slips will remain in your passport but both will be invalid on your next entry. As coming from abroad, you will need to newly register per TM30, and the 90-days report clock starts at zero