NEC 28i System Manual page 114

0501 - System Numbering
1=Service Code, 2=Extension Number, 6=Trunk Access,
Dial Types:
7=Operator Access, 8=Alternate Trunk Access, 0, 3-5=Not Used
Dialed Number of Digits Required
Number
1X
11
12
13
14
15
16
17
18
19
10
1*
1#
2X
21
22
23
24
25
26
27
28
29
20
2*
2#
4-12
System Numbering
Default New
3
0
0
0
0
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
0
0
0
0
For Your Notes
Dial Type
Default New
1
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0