diff --git a/twander.1 b/twander.1
index a6fc2ec..1338563 100644
--- a/twander.1
+++ b/twander.1
@@ -2819,8 +2819,8 @@
 It's easy to fall into the trap of treating the \*(TW
 configuration capabilities as a real "programming language".
 It is not, it is a fairly simple macro language that does
-very little more than string substitutions.  You should thus kee these
-rules in mind as you edit your configuration:
+very little more than string substitutions. 
+Keep the following rules in mind as you edit your configuration:
 
 
 .IP \(bu 4
@@ -2829,10 +2829,10 @@
 .B until they appear in a Command Definition.
 
 .IP \(bu 4
-Option Statements, Key Binding Statements, Directory Shortcut
+The Right Hand Side of Option Statements, Key Binding Statements, Directory Shortcut
 Statements, and Wildcard Statements
-.B are treated literally 
-with no variable substitution ever done to their Right Hand Side.
+.B are treated literally -
+No variable substitution is ever done there.
 
 .IP \(bu 4
 A Conditional Statement always involves a variable
@@ -2844,6 +2844,21 @@
 .B must be defined
 and any equality test must be satisfied.
 
+.IP \(bu 4
+When testing for the existence of a User-Defined or Environment
+Variable, \*(TW does not care what
+.B value
+the variable contains.  It is perfectly permissible to have
+either type of variable set to an empty string.  The fact
+that the variable exists at all is what makes the following
+construct true:
+
+.nf
+CondVar =
+\&.if [CondVar]
+  ....
+\&.endif
+
 .P
 Common mistakes include:
 
@@ -2859,17 +2874,15 @@
 #####
 # Expecting a conditional variable to be resolved before the test
 # Suppose $EDITOR is set to "/usr/local/bin/emacs" ...
-#####
-
-EDT = [$EDITOR]
-
-#####
+#
 # The following will be False because [EDT] equals
 # the string "[$EDITOR]".  It is not replaced
 # with "/usr/local/bin/emacs" until [EDT] appears
 # in a Command Definition
 #####
 
+EDT = [$EDITOR]
+
 \&.if [EDT] == /usr/local/bin/emacs
           ...
 \&.endif
@@ -2882,6 +2895,29 @@
           ...
 \&.endif
 
+#####
+# A badly formed condition is ignored (after a warning)
+# which means *all the lines following will be processed*
+# (until a valid condition statement which is False is
+# encountered).
+#####
+
+PROCESS = no
+SUBPART = no
+
+# We meant not to process the following but all the
+# lines up to the next .if statement *are* processed
+# because the bad syntax on the next line means it's ignored
+
+\&.if PROCESS != no
+    ...           # Processed!
+
+    \&.if [SUBPART] == yes   # *Now* we'll stop
+        ...
+    \&.endif
+
+\&.endif
+
 .fi