Where i put my module/class in ROR MVC architecture

I have made a module named

module ConstantModelName
 AIRPORT =  "Airport"
end

It contains all the constant values used in my application.

So where should i place this module in my application.

开发者_如何学编程

currently i placed it in lib folder in my app.

Give your valuable comments.

Thanks

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lib folder is the correct place for it