Neighborhood letter rating?

[Pat S.]

I see here or hear on the podcast that a property is described as "in a C or C+ neighborhood" or something to that effect.

What does that mean exactly? Is there a specific criteria? On a scale of what?

Or is it just a gut feel/opinion of what the neighborhood is like were A is movie-like perfect, C is your average working class neighborhood, and F is war zone?

Thanks,

Pat