What the D-S-Up means in vim?

Question

I find a .vimrc file config:

" Move selection up/down (add =gv to reindent after move)
:vmap <D-S-Up> :m-2<CR>gv
:vmap <D-S-Down> :m'>+<CR>gv

I know the D-S-Up must be a key, but what is the key?

I type:

:help D-S-Up

nothing happened

Answer 1

1. :help key-notation tells you the meaning of all those <key> notations.

2. You can't expect :help D-S-Up to do anything because:

   • it doesn't follow established patterns like i_ctrl-r,
   • it is a custom mapping and Vim only provides documentation for its own commands.

3. <D> is the Cmd key on Mac keyboards, <S> is the Shift key, and <Up> is the Up arrow key.

   So <D-S-Up> means Cmd + Shift + Up.

4. The Cmd key only works in the MacVim GUI.

5. Non-portable mappings are worthless.

6. One should use :xmap or :xnoremap for visual mode mappings, not :v*.

7. Non-recursive mappings should be used by default unless one really wants recursion.

8. Using someone else's vimrc is a bad idea.

9. By the way, here are enhanced versions of those mappings:

   nnoremap <silent> <D-S-Up>   :<C-u>move-2<CR>==
   nnoremap <silent> <D-S-Down> :<C-u>move+<CR>==
   xnoremap <silent> <D-S-Up>   :move-2<CR>gv=gv
   xnoremap <silent> <D-S-Down> :move'>+<CR>gv=gv
   

   where:

   • <silent> prevents the commands in the mapping from echoing useless info,
   • <C-u> removes any default range inserted by Vim,
   • move-2<CR> is a more readable version of m-2<CR>,
   • == re-indents the line,
   • gv=gv reselects the lines, re-indents them, and re-selects them again.

Answer 2

Have a look at Move entire line up and down in Vim

In an answer you can read (concerning the line :vmap <D-S-Up> :m-2<CR>gv):

According to the shortcuts above, pressing Cmd-Shift-Up/Down will shift the block selection up/down. "D" is the Command key in MacVim, for Windows try "C" (Control), or "A" (Alt) (eg. would be Control Alt f).

Since I don't have a Mac myself, I can't check, but it's most certainly true.