Why there is no '<cr>' completion tip when we could press '<cr>'?

Other Northbound Interfaces
1 
localhost(config)# no aaa ?
Description: AAA management
Possible completions:
  authentication   User management
  ios              Specific IOS settings

when I enter no aaa <cr> , it works ok, but when I enter no aaa ?, I wish it could show me this command could directly. I mean the following tip:

localhost(config)# no aaa ?
Description: AAA management
Possible completions:
authentication   User management
ios              Specific IOS settings
<cr>
2

In this specific case and in general, you will only get the possible carriage return entry with the question mark prompt when you have reached a specific instance of a list entry (the user list in this case). If you continue to tab to the next argument in the command line as follows:

localhost(config)# no aaa authentication users user ?
Possible completions:
  admin  oper  private  public  <cr>

This is the standard behavior of ConfD’s Cisco C-style CLI. What you are suggesting isn’t currently supported.

3

I think it is better if it show the possible carriage return entry whenever we could type enter, or if no ’ shows, forbid the user type enter key.