`:verbose map` doesn't list origin of some mappings

Question

I'm trying to debug a mapping of the key Y.

:verbose map gives the following snippet:

...
noxW           * repmo#SelfKey('W', 'B')
    Last set from ~/.dotfiles/vim/.config/vim/vimrc line 446
n  Y           * y$
o  [%            <Plug>(MatchitOperationMultiBackward)
    Last set from /usr/share/nvim/runtime/pack/dist/opt/matchit/plugin/matchit.vim line 75
...

All the other lines seem to include Last set from. Why doesn't Y?

How do I find out the source of Y mapping to y$?

Also, what's the * about? Searching :help map for \* didn't turn up anything.

I'm using neovim 0.6.0.

Answer 1

Looking at :help Y we read:

Mapped to "y$" by default. |default-mappings|

Reading there, we find:

Nvim creates the following default mappings at |startup|. You can disable any
of these in your config by simply removing the mapping, e.g. ":unmap Y".

    nnoremap Y y$
    nnoremap <C-L> <Cmd>nohlsearch<Bar>diffupdate<CR><C-L>
    inoremap <C-U> <C-G>u<C-U>
    inoremap <C-W> <C-G>u<C-W>