I seek an improvement that requires special documentation globally and per command `env`: https://github.com/scop/bash-completion/issues/452 As I understand project aim is to provide sane completions out of the box. For heavy users it is not enough. Some completions might provide extra if you tune it. **What way project intend to inform users about particular command completion features and available options?** **What way completion can be custmizable (specially prefixed env var, specially named file)?**