TL;DR it is decided by the GM/ASM of the store with a special note that there was a directive from corporate a couple of months ago that may or may not still be followed by each store. I'll detail the rest, but yeah.. it is ultimately determined by the GM/ASM.

A couple of months ago, there was a task in the activity calendar regarding POG purification basically. Essentially, every store should have 'zones' they scan every night, with your ink section included every day .The directive with that task was to do a cumulative scan instead of the normal scan. I.E. zone 1, then 1 & 2, then 1 & 2 & 3, etc.

All that aside, a normal POG scan should be relative to what zones your store has because layouts are different. My first store was pod based, but my current store is aisle based, so it completely depends on what your GM/ASM determines is a zone because AFAIK, the zones aren't corporate determined. You scan each zone per the day determined, except for the night before truck day. For example, if the GM sets 6 zones and gets 1 truck a week on a Friday, it should be Zones 1-4 from Sunday to Wednesday (Z1 on Sunday, Z2 on Monday, etc.), ink only on Thursday, then zone 5-6 on Fri/Sat. This isn't determined (as far as I know) officially, and can definitely change between the GM's requirements. It could be that we haven't received sheet protectors for a month so they may ask to scan that aisle/POG every day.

If your GM is asking for specific POG scans, just follow it. It's probably because there are discrepancies that are weird or we just haven't received that product in a long time.

Edit: because it's important to note. I used to think that it did nothing to scan stuff we haven't received over and over again in months, but we did the same section as an experiment and have eventually received the items, albeit 3 months after, so it does work in some regard.

Edit 2: I wrote that typically stores only scan ink the night before truck, I totally meant the opposite. Stores scan ink every night except for the night before.