My modules spit out warnings when you do something stupid with them, or in a few cases when there is a non-fatal error. They are intended to be useful both for programmers using my modules and for users of your modules.

I do try to remember to document what warnings I might spit out, so if you really want to hide errors from your users you can, by catching my warnings in a local $SIG{__WARN__}. Anywhere that I don't document my warnings I consider to be a bug, so please report such things using RT.