Ruler Demo

 
1
0123456789
2
          0123456789
3
                    0123456789
4
                              0123456789
5
                                        0123456789
6
                                                  0123456789
7
0123456789
8
          0123456789
9
                    0123456789
10
                              0123456789
11
                                        0123456789
12
                                                  0123456789
13
0123456789
14
          0123456789
15
                    0123456789
16
                              0123456789
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                                        0123456789
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                                                  0123456789
19
​

Demonstration of the rulers addon, which displays vertical lines at given column offsets.