[nicholasbraker]

NATO Secret is one of the highest and you definitely need to have had extensive background checks and clearances to have access to this data. From my experience this is not the type of data your typical employee (uniformed or civilian) would be in contact with.

[pbronez]

Per NATO's security guidance [0], NATO SECRET is the second-highest of ~5 classification categories It " is applied to information the unauthorized disclosure of which would cause serious damage to NATO."

In decreasing order of sensitivity, the categories are:

COSMIC TOP SECRET

NATO SECRET (NS)

NATO CONFIDENTIAL (NC)

NATO RESTRICTED (NR)

NATO UNCLASSIFIED (NU)

[0] https://www.act.nato.int/images/stories/structure/reserve/hq...

[sandworm101]

Those NATO levels are all just the start. Every NATO member runs many of their own layers. Over and above NATO come levels that are country-specific. In the US that means things like "five eyes" or US-only, which are technically secret (ie not TS) but are still above NATO. Remember that anything NATO is going to be seen by a large number of countries, including Turkey and Greece.