Assigning line ID numbers to lines and associating line appearance buttons to those lines is sufficient for answering incoming calls on those lines. However, to use line appearance buttons for outgoing calls may require further programming.

Short Codes and Outgoing Line Appearance Calls Once a line has been seized using a line appearance button, short code matching is still applied to the number dialed. That can include user, system and ARS short codes.  

The short codes matching must resolve to an off-switch number suitable to be passed direct to the line.

The final short code applied must specify a 'dial' feature. This allows call barring of specific matching numbers to be applied using short codes set to features such as 'Busy'.