1 files changed, 19 insertions, 0 deletions
diff --git a/luaotfload.dtx b/luaotfload.dtx
index 01bdeec..4fbb913 100644
--- a/luaotfload.dtx
+++ b/luaotfload.dtx
@@ -676,6 +676,25 @@ fonts.mode = "node"
 
 %    \end{macrocode}
 %
+%    The following features are useful in math (e.g. in XITS Math font),
+%    but \textsf{luaotfload} does not recognize them in |base| mode.
+%
+%    \begin{macrocode}
+
+local register_base_sub = fonts.otf.features.register_base_substitution
+local gsubs = {
+    "ss01", "ss02", "ss03", "ss04", "ss05",
+    "ss06", "ss07", "ss08", "ss09", "ss10",
+    "ss11", "ss12", "ss13", "ss14", "ss15",
+    "ss16", "ss17", "ss18", "ss19", "ss20",
+}
+
+for _,v in next, gsubs do
+    register_base_sub(v)
+end
+
+%    \end{macrocode}
+%
 %    Finally two functions
 %
 %    \begin{macrocode}