"EF" tends to be "very slight wear" or what TPGs attempt to call "AU 55 or 58." This is much closer to American usage in the 19th and early 20th centuries, before heavy influence of money and profit stimulated splitting the easter bunny into body parts.
Here is PCGS's version. Note the extensive subdivision of "grades" which tend to inflate prices. This is a characteristic of highly commercialized systems and not specific to PCGS, NGC or anyone else. https://www.pcgseurope.com/grading-comparison?l=en
[The same thing happens with cereal, toilet paper, cars, etc. More versions with slight differences mean greater profits for sellers.]