diff --git a/WordPress/Docs/NamingConventions/ValidFunctionNameStandard.xml b/WordPress/Docs/NamingConventions/ValidFunctionNameStandard.xml
new file mode 100644
index 0000000000..00b9bd4f2a
--- /dev/null
+++ b/WordPress/Docs/NamingConventions/ValidFunctionNameStandard.xml
@@ -0,0 +1,39 @@
+<?xml version="1.0"?>
+<documentation xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="https://phpcsstandards.github.io/PHPCSDevTools/phpcsdocs.xsd"
+    title="Valid Function Name"
+>
+    <standard>
+    <![CDATA[
+    Use lowercase letters in function names. Separate words using underscores. Do not use double underscores as a prefix.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: lowercase function name.">
+        <![CDATA[
+function <em>prefix_function_name()</em> {}
+        ]]>
+        </code>
+        <code title="Invalid: mixed case function name.">
+        <![CDATA[
+function <em>Prefix_Function_NAME()</em> {}
+        ]]>
+        </code>
+    </code_comparison>
+    <code_comparison>
+        <code title="Valid: words separated by underscores.">
+        <![CDATA[
+class My_Class {
+    public static <em>method_name()</em> {}
+}
+        ]]>
+        </code>
+        <code title="Invalid: using camel case to separate words.">
+        <![CDATA[
+class My_Class {
+    public static <em>methodName()</em> {}
+}
+        ]]>
+        </code>
+    </code_comparison>
+</documentation>