You specify v-scan codes when you change how keys or keysyms are mapped.

Following are the v-scan codes for the 104-key U.S. keyboard.

Table 1. V-Scan Codes for the 104-Key U.S. Keyboard
Symbol Shifted Symbol Location V-Scan Code
Esc     0x001
1 !   0x002
2 @   0x003
3 #   0x004
4 $   0x005
5 %   0x006
6 ^   0x007
7 &   0x008
8 *   0x009
9 (   0x00a
0 )   0x00b
- _   0x00c
= +   0x00d
Backspace     0x00e
Tab     0x00f
Q     0x010
W     0x011
E     0x012
R     0x013
T     0x014
Y     0x015
U     0x016
I     0x017
O     0x018
P     0x019
[ {   0x01a
] }   0x01b
Enter     0x01c
Ctrl   left 0x01d
A     0x01e
S     0x01f
D     0x020
F     0x021
G     0x022
H     0x023
J     0x024
K     0x025
L     0x026
;     0x027
'     0x028
`     0x029
Shift   left 0x02a
\ |   0x02b
Z     0x02c
X     0x02d
C     0x02e
V     0x02f
B   0x030
N     0x031
M     0x032
, <   0x033
. >   0x034
/ ?   0x035
Shift   right 0x036
*   numeric pad 0x037
Alt   left 0x038
Space bar     0x039
Caps Lock     0x03a
F1     0x03b
F2     0x03c
F3     0x03d
F4     0x03e
F5     0x03f
F6     0x040
F7     0x041
F8     0x042
F9     0x043
F10     0x044
Num Lock   numeric pad 0x045
Scroll Lock     0x046
Home 7 numeric pad 0x047
Up arrow 8 numeric pad 0x048
PgUp 9 numeric pad 0x049
- numeric pad 0x04a
Left arrow 4 numeric pad 0x04b
5 numeric pad 0x04c
Right arrow 6 numeric pad 0x04d
+ numeric pad 0x04e
End 1 numeric pad 0x04f
Down arrow 2 numeric pad 0x050
PgDn 3 numeric pad 0x051
Ins 0 numeric pad 0x052
Del   numeric pad 0x053
F11     0x057
F12     0x058
Break Pause   0x100
Enter   numeric pad 0x11c
Ctrl   right 0x11d
/   numeric pad 0x135
SysRq Print Scrn   0x137
Alt   right 0x138
Home   function pad 0x147
Up arrow   function pad 0x148
Page Up   function pad 0x149
Left arrow   function pad 0x14b
Right arrow   function pad 0x14d
End   function pad 0x14f
Down arrow   function pad 0x150
Page Down   function pad 0x151
Insert   function pad 0x152
Delete   function pad 0x153
Windows   left 0x15b
Windows   right 0x15c
Menu     0x15d

The 84-key keyboard has a Sys Req key on the numeric pad. Its v-scan code is 0x054.

Keyboards outside the U.S. usually have an extra key (often < > or < > |) next to the left Shift key. The v-scan code for this key is 0x056.