On Fri, Sep 29, 2017 at 12:32:25PM +0500, Alexander V. Makartsev wrote: > As for the "Tab" key, it is essentially an auto-complete function when > you use it in your console. It just much more convenient to see what > options and parameters are available to use with pactl, or other console > programs that support it.
I believe you're talking about bash-completion, or the zsh equivalent. This is a separate package (bash-completion 1:2.1-4.3 in stretch), which is sourced by the default ~/.bashrc file, and which provides tab completion voodoo for many Debian commands. And which is also known to cause some problems, so... your choice whether to keep using it or not.