Update runtime files
diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index 0101b51..35a4e3a 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -4506,7 +4506,7 @@
changes the \z1 back-reference into an external reference referring to the
first external sub-expression in the start pattern. External references can
also be used in skip patterns: >
- :syn region foo start="start \(\I\i*\)" skip="not end \z1" end="end \z1"
+ :syn region foo start="start \z(\I\i*\)" skip="not end \z1" end="end \z1"
Note that normal and external sub-expressions are completely orthogonal and
indexed separately; for instance, if the pattern "\z(..\)\(..\)" is applied