#Tip27: Meet Vim's Command Line
##:
switch into Command-Line mode.
##:h ex-cmd-index
command list
##:<C-w> <C-u> (Insert || Command-Line)
delete backward to the strong1art of the previous word
delete backward to the start of the line
##:<C-v> <C-k>
insert characters that are not found on the keyboard.
##:<C-r>{register}
insert thate contents of any register at the command line.