What do the little rectangular marks on food packets mean?

[Stephen Tashiro]

Inside its box, dried food (e.g. Zatrains Black Beans And Rice) often comes in a packet that has no markings on it except for a small rectangular mark near the top of the packet. Is this mark supposed to indicate a location for opening the packet? (It never opens there for me.) Or is it just something used in the manufacturing process - perhaps a mark so a sensor can automatically detect the packet?

[Brian Brown]

Your second guess is right. The marks are detected by an optical sensor on the handling machinery. The inner bag is streached in a circle around the spout that fills the bag. Then after filling, it moves to a crimper that turns the bag orientation (with the assistance of the rectangle), and now the bag can be crimped shut in a way that allows the top crimp to be in the same plane as the bottom crimp. The bag fits in the box much better that way.

[Rich Engelhardt]

Those are RFID chips that can be activated via remote control if/when the forces of evil take over our government and force people to hide out underground and live off of their secret food stash so **they** can track people.

(or they could be part of a simple optical sensor system.)

Personally, I like the former story better.....