[arc776]

> you often have quasi-singleton classes called "FooManager", then a single instance called "foo_manager".

Like this:

    type FooManager = object
    var foo_manager: FooManager

> Now... are these colliding? Or not, because the first letter _is_ case-sensitive?

Well as you correctly reason, the first letter's case distinguishes them.

Convention in the language is for types to start with a capital letter and instances start with a lower case letter.

> What does "fooManager" map to then?

It maps to the `foo_manager` instance because underscores are ignored, they're just for you. By the way, underscores are exceedingly rarely used in Nim code because they're not semantically significant, why bother.

Still, if you like you can use them in your code, and others can choose not to as they want. Clashing identifiers are a compile error so no worries.