diff --git a/xCAT-client/pods/man1/chdef.1.pod b/xCAT-client/pods/man1/chdef.1.pod
index 5a02b6cc6..c0dcaa6b7 100644
--- a/xCAT-client/pods/man1/chdef.1.pod
+++ b/xCAT-client/pods/man1/chdef.1.pod
@@ -58,6 +58,12 @@ Verbose mode.
 
 Use one or multiple -w flags to specify the selection string that can be used to select objects. The operators ==, !=, =~ and !~ are available. Use the help option to get a list of valid attributes for each object type.
 
+Operator descriptions:
+        ==        Select nodes where the attribute value is exactly this value.
+        !=        Select nodes where the attribute value is not this specific value.
+        =~        Select nodes where the attribute value matches this regular expression.
+        !~        Select nodes where the attribute value does not match this regular expression.
+
 Note: the operator !~ will be parsed by shell, if you want to use !~ in the selection string, use single quote instead. For example:-w 'mgt!~ipmi'.
 
 =item B<-z|--stanza>
diff --git a/xCAT-client/pods/man1/lsdef.1.pod b/xCAT-client/pods/man1/lsdef.1.pod
index 50af3af8a..0ef7fe535 100644
--- a/xCAT-client/pods/man1/lsdef.1.pod
+++ b/xCAT-client/pods/man1/lsdef.1.pod
@@ -58,6 +58,12 @@ Verbose mode.
 
 Use one or multiple -w flags to specify the selection string that can be used to select objects. The operators ==, !=, =~ and !~ are available. Use the help option to get a list of valid attributes for each object type.
 
+Operator descriptions:
+        ==        Select nodes where the attribute value is exactly this value.
+        !=        Select nodes where the attribute value is not this specific value.
+        =~        Select nodes where the attribute value matches this regular expression.
+        !~        Select nodes where the attribute value does not match this regular expression.
+
 Note: if the "val" fields includes spaces or any other characters that will be parsed by shell, the "attr<operator>val" needs to be quoted. If the operator is "!~", the "attr<operator>val" needs to be quoted using single quote.
 
 =item B<-z|--stanza>
diff --git a/xCAT-client/pods/man1/mkdef.1.pod b/xCAT-client/pods/man1/mkdef.1.pod
index 9e6101206..4d276d842 100644
--- a/xCAT-client/pods/man1/mkdef.1.pod
+++ b/xCAT-client/pods/man1/mkdef.1.pod
@@ -56,6 +56,12 @@ Verbose mode.
 
 Use one or multiple -w flags to specify the selection string that can be used to select objects. The operators ==, !=, =~ and !~ are available. For mkdef commmand, the -w flag only makes sense for creating dynamic node group. Use the help option to get a list of valid attributes for each object type.
 
+Operator descriptions:
+        ==        Select nodes where the attribute value is exactly this value.
+        !=        Select nodes where the attribute value is not this specific value.
+        =~        Select nodes where the attribute value matches this regular expression.
+        !~        Select nodes where the attribute value does not match this regular expression.
+
 Note: if the "val" fields includes spaces or any other characters that will be parsed by shell, the "attr<operator>val" needs to be quoted. If the operator is "!~", the "attr<operator>val" needs to be quoted using single quote.
 
 =item B<-z|--stanza>