user_displayname test
0 : $(user_displayname)
1 : $(user_displayname:1)
2 : $(user_displayname:2)
3 : $(user_displayname:3)
4 : $(user_displayname:4)
5 : $(user_displayname:5)
6 : $(user_displayname:6)
7 : $(user_displayname:7)
8 : $(user_displayname:8)
9 : $(user_displayname:9)
10 : $(user_displayname:10)
11 : $(user_displayname:11)
12 : $(user_displayname:12)