Understanding "Class" of buildings

[Joe Smith]

Hi - I have experience in SFR and 2 unit properties and am looking to delve into larger 5+ MF.

How do you determine if a property is Class A, B etc?

Examples: I presume a Class A would be a 110 unit, higher-end property with onsite excercise room, underground parking, large apartments, newer construction or rehab, etc, in an "important" market like, Chicago.

Is there a size/number of units restriction?

But what about others? Is a city like Cleveland unable to have a Class A? What about a smaller market like Canton, Ohio?

Here is a specific example - this one isn't for sale but I know the owner. A 20-unit, single building, with 1BR units that rent for $400 - $500 per month. There is parking, but no real amenities besides a laundry room. Units are clean, well maintained, and functional, but low-end. Property is not that old, built in 1990. Worth maybe $600k but according to the owner the cap rate is around 9% based on that value.

Is that a Class B or Class C? Or does that fall outside that description due to the small nature of the property?

What about something in a Cleveland suburb with 25 units that rents for $600/mo per unit, built in the mid 90s, well maintaned, with free wi-fi, good (but uncovered) parking, in-unit laundry? Say it just sold for $1.25M?

Still a C, or would that maybe meet "B" criteria?

How about the many old, 5-10 unit buildings that are under $300k in these markets?