Blue numbers, left of the numbers

[ReneFroger]

First, thanks for sharing your Vimrc.

I noticed there are blue numbers at the left of your numbers, in your screenshot. I was curious what these numbers mean. I looked into your Bundle map, but I couldn't find any related plugin. Could you tell which plugin it is?

Thanks in advance!

[DamZiobro]

Those are markers (http://www.cs.oberlin.edu/~kuperman/help/vim/markers.html). You can use it to mark some important places in code (text) and quickly move between them. To set up marker k you are using: mk in normal mode. To go to marker k you can use: 'k