NERDCommenterYank yanks to the default unnamed register "". Like all other yanking/pasting in vim, this is a good default, but it's also nice to be able to choose a register. One use case is creating a “comment and duplicate” function/mapping without clobbering the default register, as discussed in #435.

I don't know the internals or the right syntax, but from a UX perspective, I would hope for all of the following:

• ["x][count]<leader>cy - Support standard register specification for NERDCommenterYank mapping, as with ["x]yy and friends.
• ["x]<plug>NERDCommenterYank, <plug>NERDCommenterYank({register}), or similar way to specify a register when invoking this way (e.g. in a user-defined function or mapping).
• NERDComment({mode}, {type}, [{register}]) - Specify register when type=Yank.
• let g:NerdYankRegister = x - Set default register used by NERDCommenterYank.