Meaning that is displayed by [alternatives --config mta] is what?

Question

The following screen appears when run [alternatives --config mta].

There are 2 programs which provide 'mta'.

  Selection    Command
-----------------------------------------------
 + 1           /usr/sbin/sendmail.postfix
*  2           /usr/sbin/sendmail.sendmail

Enter to keep the current selection[+], or type selection number: 

1. What does asterisk(*) mean?
2. What does plus(+) mean?

Helminth

Answer 1

The asterisk (`*) indicates the option that the alternatives software believes is "best" and would use if auto mode is selected.

Catfall

It is incredible, IMO, that this information is not in the man page. – Windcheater

What's more incredible is how everybody seemingly forgot to address what the plus (+) means. – Algicide

Answer 2

In alternatives, each link has a priority which you set when you use alternatives --install or it is set automatically for you. The priority is used to choose the link when alternatives is in auto mode.

The asterisk indicates the link with the highest priority.

Morna

Answer 3

Addressing @christian hilarious comment on the accepted best answer by @rupert160:

1. What does asterisk(*) mean? This is the 'best' version as established by the auto-install priorities. Check alternatives --display mta to understand the priority given to each installation (appear as an integer).
2. What does plus(+) mean? This is the current selection. Many people did not comment on that since it can be read from the output directly when executing alternatives --config mta:

Enter to keep the current selection[+], or type selection number:

Promptitude