Are IVY Default Repositories Mandatory?

[Buck, Robert]

Good morning,
 
The documentation states:
 
"This default settings mainly consist of 3 kind of repositories...
First, several repositories uses the same root in your filesystem.
Referenced as ${ivy.default.ivy.user.dir}, this is by default the
directory .ivy2 in your user home."
 
Is this to imply that the local, shared, and public repositories are
mandatory?
 
>From my use it seems that local is mandatory since though I set up my
own custom resolvers, caches, and repositories, I still get stuff in
${user.home}.
 
Bob