diff --git a/runtime/syntax/testdir/input/vim_expr.vim b/runtime/syntax/testdir/input/vim_expr.vim
index 0547e9b..be2cb2c 100644
--- a/runtime/syntax/testdir/input/vim_expr.vim
+++ b/runtime/syntax/testdir/input/vim_expr.vim
@@ -4,6 +4,23 @@
 echo 'tab: \t, new line: \n, backslash: \\'
 echo "tab: \t, new line: \n, backslash: \\"
 
+" String escape sequences
+
+echo "\316 - \31 - \3 - \x1f - \xf - \X1F - \XF - \u02a4 - \U000002a4 - \b - \e - \f - \n - \r - \t - \\ - \" - \<C-W>"
+echo '\316 \31 \3 \x1f \xf \X1F \XF \u02a4 \U000002a4 \b \e \f \n \r \t \\ \" \<C-W>'
+echo "\3160 - \x1f0 - \X1F0 - \u02a40 - \U000002a40"
+
+echo $"\316 - \31 - \3 - \x1f - \xf - \X1F - \XF - \u02a4 - \U000002a4 - \b - \e - \f - \n - \r - \t - \\ - \" - \<C-W>"
+echo $'\316 \31 \3 \x1f \xf \X1F \XF \u02a4 \U000002a4 \b \e \f \n \r \t \\ \" \<C-W>'
+echo $"\3160 - \x1f0 - \X1F0 - \u02a40 - \U000002a40"
+
+echo "\<C-a>"
+echo "\<*C-a>"
+echo "\<C->>"
+echo "\<*C->>"
+echo "\<C->>>"
+echo "\<*C->>>"
+
 " String interpolation
 
 echo 'Don''t highlight interpolation: {{ {1 + 2} }}'
@@ -12,3 +29,4 @@
 echo $'Highlight interpolation:\t{{ { $'nested: {{ {1 + 2} }}' } }}'
 echo $"Highlight interpolation:\t{{ { string({"foo": "bar"}) } }}"
 echo $"Highlight interpolation:\t{{ { $"nested: {{ {1 + 2} }}" } }}"
+
diff --git a/runtime/syntax/testdir/input/vim_key_notation.vim b/runtime/syntax/testdir/input/vim_key_notation.vim
new file mode 100644
index 0000000..8bc128a
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim_key_notation.vim
@@ -0,0 +1,163 @@
+" Key notation
+ 
+<Space>
+<Tab>
+<Tab>
+<NL>
+<NewLine>
+<LineFeed>
+<LF>
+<CR>
+<Return>
+<Enter>
+<BS>
+<BackSpace>
+<Esc>
+<CSI>
+<xCSI>
+<Bar>
+<Bslash>
+<Del>
+<Delete>
+<kDel>
+<Up>
+<Down>
+<Left>
+<Right>
+<xUp>
+<xDown>
+<xLeft>
+<xRight>
+<PasteStart>
+<PasteEnd>
+<F1>
+<F2>
+<F3>
+<F4>
+<F5>
+<F6>
+<F7>
+<F8>
+<F9>
+<F10>
+<F11>
+<F12>
+<F13>
+<F14>
+<F15>
+<F16>
+<F17>
+<F18>
+<F19>
+<F20>
+<F21>
+<F22>
+<F23>
+<F24>
+<F25>
+<F26>
+<F27>
+<F28>
+<F29>
+<F30>
+<F31>
+<F32>
+<F33>
+<F34>
+<F35>
+<F36>
+<F37>
+<xF1>
+<xF2>
+<xF3>
+<xF4>
+<Help>
+<Undo>
+<Insert>
+<Ins>
+<kInsert>
+<Home>
+<kHome>
+<xHome>
+<zHome>
+<End>
+<kEnd>
+<xEnd>
+<zEnd>
+<PageUp>
+<PageDown>
+<kPageUp>
+<kPageDown>
+<kPlus>
+<kMinus>
+<kDivide>
+<kMultiply>
+<kEnter>
+<kPoint>
+<k0>
+<k1>
+<k2>
+<k3>
+<k4>
+<k5>
+<k6>
+<k7>
+<k8>
+<k9>
+<lt>
+<Mouse>
+<NetMouse>
+<DecMouse>
+<JsbMouse>
+<PtermMouse>
+<UrxvtMouse>
+<SgrMouse>
+<SgrMouseRelease>
+<LeftMouse>
+<LeftMouseNM>
+<LeftDrag>
+<LeftRelease>
+<LeftReleaseNM>
+<MouseMove>
+<MiddleMouse>
+<MiddleDrag>
+<MiddleRelease>
+<RightMouse>
+<RightDrag>
+<RightRelease>
+<ScrollWheelUp>
+<ScrollWheelDown>
+<ScrollWheelRight>
+<ScrollWheelLeft>
+<MouseDown>
+<MouseUp>
+<X1Mouse>
+<X1Drag>
+<X1Release>
+<X2Mouse>
+<X2Drag>
+<X2Release>
+<Drop>
+<Nul>
+<SNR>
+<Plug>
+<CursorHold>
+<Ignore>
+<Cmd>
+<ScriptCmd>
+<FocusGained>
+<FocusLost>
+
+<cword>
+<cWORD>
+<cexpr>
+<cfile>
+<afile>
+<abuf>
+<amatch>
+<sfile>
+<stack>
+<script>
+<slnum>
+<sflnum>
+<client>