1. Use nnoremap to define macros that will be executed in command mode
   • Syntax: nnoremap <KEY_ACTION> <ACTION_TO_TAKE>
   • E.g.: Toggle NERDTree sidebar using \\ + f:

     nnoremap <Leader>f :NERDTreeToggle<Enter>
     

   • (Important) <Leader>: A “mapleader” variable, useful for defining custom mappings without collision with existing mappings (typically set to \\)
   • There are also different variants such as cnoremap, vnoremap, etc.; refer to :help nnoremap for details
2. Symbol notations for non-letter keys provided by Vim
   • Notation provided to enhance readability of mapping definitions
   • E.g.: <Space>, <Esc>, <Del>
   • <CR>: Carriage Return (= <Enter>, <Return>)
   • Run :help key-notation to see a full list of such symbols
3. Mappings predefined by Vim
   • E.g. <C-r><C-w> inserts the word currently under the cursor
     • E.g. Start off a global substitution command for exact matches of the word under cursor:

       nnoremap <Leader>s :%s/\<<C-r><C-w>\>/
       

   • c_ prefix means that the mapping works in command mode
   • Refer to :help cmdline for more details
4. Use :help <ITEM_TO_SEARCH> to search for occurrence of <ITEM_TO_SEARCH> in Vim manual, e.g. :help <Leader>, :help <C-r>
   • <ITEM_TO_SEARCH> doesn’t have to be a complete (key)word; lookup based on a part of (key)word is also supported

References:

• https://stackoverflow.com/questions/1764263/what-is-the-leader-in-a-vimrc-file
• https://stackoverflow.com/questions/22142755/what-is-the-meaning-of-a-cr-at-the-end-of-some-vim-mappings
• https://vi.stackexchange.com/questions/22034/how-to-execute-with-call-and-c-r-matching