diff --git a/doc/c128.sgml b/doc/c128.sgml
index a2ef0829b..95d130608 100644
--- a/doc/c128.sgml
+++ b/doc/c128.sgml
@@ -265,6 +265,12 @@ does not exist).
 Command line argument passing is currently not supported for the C128.
 
 
+<sect1>Program return code<p>
+
+The program return code (low byte) is passed back to BASIC by use of the
+<tt/ST/ variable.
+
+
 <sect1>Interrupts<p>
 
 The runtime for the C128 uses routines marked as <tt/.CONDES/ type 2 for
diff --git a/doc/c16.sgml b/doc/c16.sgml
index 494e6d8c6..d950940be 100644
--- a/doc/c16.sgml
+++ b/doc/c16.sgml
@@ -203,6 +203,11 @@ library, because the latter does not support interrupts needed by the driver.
 Command line argument passing is currently not supported for the C16/C116.
 
 
+<sect1>Program return code<p>
+
+The program return code (low byte) is passed back to BASIC by use of the
+<tt/ST/ variable.
+
 
 
 <sect>Bugs/Feedback<p>
diff --git a/doc/c64.sgml b/doc/c64.sgml
index 46c9b01aa..5aac45af2 100644
--- a/doc/c64.sgml
+++ b/doc/c64.sgml
@@ -263,6 +263,11 @@ supported by BASIC, the following syntax was choosen:
 </enum>
 
 
+<sect1>Program return code<p>
+
+The program return code (low byte) is passed back to BASIC by use of the
+<tt/ST/ variable.
+
 
 <sect>Bugs/Feedback<p>
 
diff --git a/doc/cbm610.sgml b/doc/cbm610.sgml
index 5a4d18cfb..cafe55b26 100644
--- a/doc/cbm610.sgml
+++ b/doc/cbm610.sgml
@@ -249,6 +249,12 @@ Command line argument passing is currently not supported for the Commodore
 610.
 
 
+<sect1>Program return code<p>
+
+The program return code (low byte) is passed back to BASIC by use of the
+<tt/ST/ variable.
+
+
 <sect1>Interrupts<p>
 
 The runtime for the Commodore 610 uses routines marked as <tt/.CONDES/ type 2
diff --git a/doc/plus4.sgml b/doc/plus4.sgml
index 93d5c15e2..4d9a9d909 100644
--- a/doc/plus4.sgml
+++ b/doc/plus4.sgml
@@ -185,7 +185,7 @@ does not exist).
   that because of the peculiarities of the 6551 chip transmits are not
   interrupt driven, and the transceiver blocks if the receiver asserts flow
   control because of a full buffer.
-                                                               
+
   You need an adapter to use the builtin port, since the output levels
   available at the user port don't follow the RS232 standard.
 
@@ -204,6 +204,12 @@ does not exist).
 Command line argument passing is currently not supported for the Plus/4.
 
 
+<sect1>Program return code<p>
+
+The program return code (low byte) is passed back to BASIC by use of the
+<tt/ST/ variable.
+
+
 <sect1>Interrupts<p>
 
 The runtime for the Plus/4 uses routines marked as <tt/.CONDES/ type 2 for