See [this stackoverflow question](https://stackoverflow.com/questions/1764263/what-is-the-leader-in-a-vimrc-file) and also [Learn Vimscript the hard way](https://learnvimscriptthehardway.stevelosh.com/)

The <Leader> key is mapped to \ by default. So if you have a map of <Leader>t, you can execute it by default with \+t. For more detail or re-assigning it using the mapleader variable, see