When pressed, the button invokes the same process as dialing Feature 0.
If Feature 0 is followed by a 3-digit index number in the range 000 to 999, the system directory entry with the matching index number is dialed.
If Feature 0 is followed by * and a 2-digit index number in the range 00 to 99, the personal directory entry with the matching index number is dialed. Note: Release 10.0 allows users to have up to 250 personal directory entries. However, only 100 of those can be assigned index numbers.
