Location of ini/config files in linux/unix?

Question

Two questions, really:

1. Is there a standard/convention regarding the placement on configuration files?

   For system or quasi-system programs they see

Answer 1

1. Generally system/global config is stored somewhere under /etc.
2. User-specific config is stored in the user's home directory, often as a hidden file, sometimes as a hidden directory containing non-hidden files (and possibly more subdirectories).

Generally speaking, command line options will override environment variables which will override user defaults which will override system defaults.