diff --git a/runtime/doc/if_mzsch.txt b/runtime/doc/if_mzsch.txt
index da43829..6420856 100644
--- a/runtime/doc/if_mzsch.txt
+++ b/runtime/doc/if_mzsch.txt
@@ -39,7 +39,7 @@
 :[range]mz[scheme] {stmt}
 			Execute MzScheme statement {stmt}.
 
-:[range]mz[scheme] << [endmarker]
+:[range]mz[scheme] << [trim] [{endmarker}]
 {script}
 {endmarker}
 			Execute inlined MzScheme script {script}.
@@ -47,12 +47,11 @@
 			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.
+			|:append| and |:insert| commands.  Refer to
+			|:let-heredoc| for more information.
+
 
 							*:mzfile* *:mzf*
 :[range]mzf[ile] {file}	Execute the MzScheme script in {file}.