diff --git a/.config/vim/vimrc.d/40-keys.vim b/.config/vim/vimrc.d/40-keys.vim
index ece67d4..04b3be4 100644
--- a/.config/vim/vimrc.d/40-keys.vim
+++ b/.config/vim/vimrc.d/40-keys.vim
@@ -540,4 +540,6 @@ augroup qf_centered_enter
 augroup END
 
 " TODO: make `gf` open absolute paths relative to PWD if possible
+" TODO: operator pending mode: [ia]$ in shell scripts to select the current
+"       parameter expansion or command substitution
 "