Update runtime files.
diff --git a/runtime/doc/if_mzsch.txt b/runtime/doc/if_mzsch.txt
index 7b7e6b1..c6888a8 100644
--- a/runtime/doc/if_mzsch.txt
+++ b/runtime/doc/if_mzsch.txt
@@ -1,4 +1,4 @@
-*if_mzsch.txt*  For Vim version 8.1.  Last change: 2019 May 05
+*if_mzsch.txt*  For Vim version 8.1.  Last change: 2019 Jul 21
 
 
 		  VIM REFERENCE MANUAL    by Sergey Khorev
@@ -39,7 +39,7 @@
 :[range]mz[scheme] {stmt}
 			Execute MzScheme statement {stmt}.
 
-:[range]mz[scheme] << {endmarker}
+:[range]mz[scheme] << [endmarker]
 {script}
 {endmarker}
 			Execute inlined MzScheme script {script}.
@@ -47,6 +47,13 @@
 			feature wasn't compiled in.  To avoid errors, see
 			|script-here|.
 
+			The {endmarker} below the {script} must NOT be
+			preceded by any white space.
+
+			If [endmarker] is omitted from after the "<<", a dot
+			'.' must be used after {script}, like for the
+			|:append| and |:insert| commands.
+
 							*:mzfile* *:mzf*
 :[range]mzf[ile] {file}	Execute the MzScheme script in {file}.