diff --git a/oval-schemas/independent-definitions-schema.xsd b/oval-schemas/independent-definitions-schema.xsd
index 12b1610..4de5704 100644
--- a/oval-schemas/independent-definitions-schema.xsd
+++ b/oval-schemas/independent-definitions-schema.xsd
@@ -1480,9 +1480,9 @@
                                           <xsd:annotation>
                                                 <xsd:documentation>The instance entity calls out a specific match of the pattern. This can only be a positive integer.</xsd:documentation>
                                                 <xsd:appinfo>
-                                                      <sch:pattern id="win-def_tfc54_i">
-                                                            <sch:rule context="win-def:textfilecontent54_state/win-def:instance">
-                                                                  <sch:assert test="string-length(.) = 0 or number(.) &lt; 1"><sch:value-of select="../@id"/> - the value of instance must be greater than one</sch:assert>
+                                                      <sch:pattern id="ind-def_tfc54_i">
+                                                            <sch:rule context="ind-def:textfilecontent54_state/ind-def:instance">
+                                                                  <sch:assert test="(@var_ref and string-length(.)=0) or (number(.) &gt;= 1)"><sch:value-of select="../@id"/> - the value of instance must be greater than or equal to one, or empty if var_ref is used.</sch:assert>
                                                             </sch:rule>
                                                       </sch:pattern>
                                                 </xsd:appinfo>
diff --git a/oval-schemas/independent-system-characteristics-schema.xsd b/oval-schemas/independent-system-characteristics-schema.xsd
index c178831..f34a5ff 100644
--- a/oval-schemas/independent-system-characteristics-schema.xsd
+++ b/oval-schemas/independent-system-characteristics-schema.xsd
@@ -461,9 +461,9 @@
                                      <xsd:annotation>
                                            <xsd:documentation>The instance entity calls out which match of the pattern is being represented by this item.  The first match is given an instance value of 1, the second match is given an instance value of 2, and so on.  The main purpose of this entity is too provide uniqueness for different textfilecontent_items that results from multiple matches of a given pattern against the same file.</xsd:documentation>
                                            <xsd:appinfo>
-                                                 <sch:pattern id="win-sc_tfc_i">
-                                                       <sch:rule context="win-sc:textfilecontent_item/win-sc:instance">
-                                                             <sch:assert test="string-length(.) = 0 or number(.) &lt; 1"><sch:value-of select="../@id"/> - the value of instance must be greater than one</sch:assert>
+                                                 <sch:pattern id="ind-sc_tfc_i">
+                                                       <sch:rule context="ind-sc:textfilecontent_item/ind-sc:instance">
+                                                           <sch:assert test="number(.) &gt;= 1"><sch:value-of select="../@id"/> - the value of instance must be greater than or equal to one</sch:assert>
                                                        </sch:rule>
                                                  </sch:pattern>
                                            </xsd:appinfo>
diff --git a/oval-schemas/unix-definitions-schema.xsd b/oval-schemas/unix-definitions-schema.xsd
index c91406e..903720e 100644
--- a/oval-schemas/unix-definitions-schema.xsd
+++ b/oval-schemas/unix-definitions-schema.xsd
@@ -276,7 +276,7 @@
                                                 <xsd:appinfo>
                                                       <sch:pattern id="unix-def_file_gid">
                                                             <sch:rule context="unix-def:file_state/unix-def:group_id">
-                                                                  <sch:assert test="string-length(.) = 0 or number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of group_id must be greater than zero</sch:assert>
+                                                                  <sch:assert test="(@var_ref and string-length(.)=0) or (number(.) &gt;= 0)"><sch:value-of select="../@id"/> - the value of group_id must be greater than or equal to zero, or empty if var_ref is used.</sch:assert>
                                                             </sch:rule>
                                                       </sch:pattern>
                                                 </xsd:appinfo>
@@ -302,7 +302,7 @@
                                                 <xsd:appinfo>
                                                       <sch:pattern id="unix-def_file_uid">
                                                             <sch:rule context="unix-def:file_state/unix-def:user_id">
-                                                                  <sch:assert test="string-length(.) = 0 or number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of user_id must be greater than zero</sch:assert>
+                                                                  <sch:assert test="(@var_ref and string-length(.)=0) or (number(.) &gt;= 0)"><sch:value-of select="../@id"/> - the value of user_id must be greater than or equal to zero, or empty if var_ref is used.</sch:assert>
                                                             </sch:rule>
                                                       </sch:pattern>
                                                 </xsd:appinfo>
diff --git a/oval-schemas/unix-system-characteristics-schema.xsd b/oval-schemas/unix-system-characteristics-schema.xsd
index 069f2c8..ab7a428 100644
--- a/oval-schemas/unix-system-characteristics-schema.xsd
+++ b/oval-schemas/unix-system-characteristics-schema.xsd
@@ -90,7 +90,7 @@
                                         <xsd:appinfo>
                                               <sch:pattern id="unix-sc_file_gid">
                                                     <sch:rule context="unix-sc:file_item/unix-sc:group_id">
-                                                          <sch:assert test="string-length(.) = 0 or number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of group_id must be greater than zero</sch:assert>
+                                                         <sch:assert test="number(.) &gt;= 0"><sch:value-of select="../@id"/> - the value of group_id must be greater than or equal to zero</sch:assert>
                                                     </sch:rule>
                                               </sch:pattern>
                                         </xsd:appinfo>
@@ -116,7 +116,7 @@
                                         <xsd:appinfo>
                                               <sch:pattern id="unix-sc_file_uid">
                                                     <sch:rule context="unix-sc:file_item/unix-sc:user_id">
-                                                          <sch:assert test="string-length(.) = 0 or number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of user_id must be greater than zero</sch:assert>
+                                                         <sch:assert test="number(.) &gt;= 0"><sch:value-of select="../@id"/> - the value of user_id must be greater than or equal to zero</sch:assert>
                                                     </sch:rule>
                                               </sch:pattern>
                                         </xsd:appinfo>
diff --git a/oval-schemas/windows-definitions-schema.xsd b/oval-schemas/windows-definitions-schema.xsd
index 12252f0..f4436d6 100644
--- a/oval-schemas/windows-definitions-schema.xsd
+++ b/oval-schemas/windows-definitions-schema.xsd
@@ -3688,7 +3688,7 @@
                                                 <xsd:appinfo>
                                                       <sch:pattern id="win-def_lps_fl">
                                                             <sch:rule context="win-def:lockoutpolicy_state/win-def:force_logoff">
-                                                                  <sch:assert test="string-length(.) = 0 or number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of force_logoff must be greater than or equal to zero</sch:assert>
+                                                                  <sch:assert test="(@var_ref and string-length(.)=0) or (number(.) &gt;= 0)"><sch:value-of select="../@id"/> - the value of force_logoff must be greater than or equal to zero, or empty if var_ref is used.</sch:assert>
                                                             </sch:rule>
                                                       </sch:pattern>
                                                 </xsd:appinfo>
@@ -3700,7 +3700,7 @@
                                                 <xsd:appinfo>
                                                       <sch:pattern id="win-def_lps_ld">
                                                             <sch:rule context="win-def:lockoutpolicy_state/win-def:lockout_duration">
-                                                                  <sch:assert test="string-length(.) = 0 or number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of lockout_duration must be greater than or equal to zero</sch:assert>
+                                                                  <sch:assert test="(@var_ref and string-length(.)=0) or (number(.) &gt;= 0)"><sch:value-of select="../@id"/> - the value of lockout_duration must be greater than or equal to zero, or empty if var_ref is used.</sch:assert>
                                                             </sch:rule>
                                                       </sch:pattern>
                                                 </xsd:appinfo>
@@ -4161,7 +4161,7 @@
                                                 <xsd:appinfo>
                                                       <sch:pattern id="win-def_pwp_mpa">
                                                             <sch:rule context="win-def:passwordpolicy_state/win-def:max_passwd_age">
-                                                                  <sch:assert test="number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of max_passwd_age must be greater than or equal to zero</sch:assert>
+                                                                  <sch:assert test="(@var_ref and string-length(.)=0) or (number(.) &gt;= 0)"><sch:value-of select="../@id"/> - the value of max_passwd_age must be greater than or equal to zero, or empty if var_ref is used.</sch:assert>
                                                             </sch:rule>
                                                       </sch:pattern>
                                                 </xsd:appinfo>
diff --git a/oval-schemas/windows-system-characteristics-schema.xsd b/oval-schemas/windows-system-characteristics-schema.xsd
index 4dba96f..3ff5091 100644
--- a/oval-schemas/windows-system-characteristics-schema.xsd
+++ b/oval-schemas/windows-system-characteristics-schema.xsd
@@ -1552,7 +1552,7 @@
                                         <xsd:appinfo>
                                               <sch:pattern id="win-sc_lpi_fl">
                                                     <sch:rule context="win-sc:lockoutpolicy_item/win-sc:force_logoff">
-                                                          <sch:assert test="string-length(.) = 0 or number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of force_logoff must be greater than or equal to zero</sch:assert>
+                                                         <sch:assert test="number(.) &gt;= 0"><sch:value-of select="../@id"/> - the value of force_logoff must be greater than or equal to zero</sch:assert>
                                                     </sch:rule>
                                               </sch:pattern>
                                         </xsd:appinfo>
@@ -1564,7 +1564,7 @@
                                         <xsd:appinfo>
                                               <sch:pattern id="win-sc_lpi_ld">
                                                     <sch:rule context="win-sc:lockoutpolicy_item/win-sc:lockout_duration">
-                                                          <sch:assert test="string-length(.) = 0 or number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of lockout_duration must be greater than or equal to zero</sch:assert>
+                                                         <sch:assert test="number(.) &gt;= 0"><sch:value-of select="../@id"/> - the value of lockout_duration must be greater than or equal to zero</sch:assert>
                                                     </sch:rule>
                                               </sch:pattern>
                                         </xsd:appinfo>
@@ -1748,7 +1748,7 @@
                                         <xsd:appinfo>
                                               <sch:pattern id="win-sc_pwp_mpa">
                                                     <sch:rule context="win-sc:passwordpolicy_item/win-sc:max_passwd_age">
-                                                          <sch:assert test="number(.) &lt; 0"><sch:value-of select="../@id"/> - the value of max_passwd_age must be greater than or equal to zero</sch:assert>
+                                                         <sch:assert test="number(.) &gt;= 0"><sch:value-of select="../@id"/> - the value of max_passwd_age must be greater than or equal to zero</sch:assert>
                                                     </sch:rule>
                                               </sch:pattern>
                                         </xsd:appinfo>