diff --git a/reference/random/functions/random-bytes.xml b/reference/random/functions/random-bytes.xml
index 003e48a57ff0..3a953c8917ec 100644
--- a/reference/random/functions/random-bytes.xml
+++ b/reference/random/functions/random-bytes.xml
@@ -13,7 +13,7 @@
    <methodparam><type>int</type><parameter>length</parameter></methodparam>
   </methodsynopsis>
   <para>
-   Generates a string containing uniformly selected random bytes with the requested length.
+   Generates a string containing uniformly selected random bytes with the requested <parameter>length</parameter>.
   </para>
   <para>
    As the returned bytes are selected completely randomly, the resulting string is likely
diff --git a/reference/random/random/randomizer/getbytes.xml b/reference/random/random/randomizer/getbytes.xml
index e63ed1ca2c22..b8f0880a9544 100644
--- a/reference/random/random/randomizer/getbytes.xml
+++ b/reference/random/random/randomizer/getbytes.xml
@@ -12,7 +12,7 @@
    <methodparam><type>int</type><parameter>length</parameter></methodparam>
   </methodsynopsis>
   <para>
-   Generates a string containing uniformly selected random bytes with the requested length.
+   Generates a string containing uniformly selected random bytes with the requested <parameter>length</parameter>.
   </para>
   <para>
    As the returned bytes are selected completely randomly, the resulting string is likely
@@ -28,7 +28,7 @@
     <term><parameter>length</parameter></term>
     <listitem>
      <para>
-      The length of the random string that should be returned in bytes; must be <literal>1</literal> or greater.
+      The length of the random &string; that should be returned in bytes; must be <literal>1</literal> or greater.
      </para>
     </listitem>
    </varlistentry>
@@ -38,7 +38,7 @@
  <refsect1 role="returnvalues">
   &reftitle.returnvalues;
   <para>
-   A string containing the requested number of random bytes.
+   A &string; containing the requested number of random bytes.
   </para>
  </refsect1>
 
diff --git a/reference/random/random/randomizer/getbytesfromstring.xml b/reference/random/random/randomizer/getbytesfromstring.xml
index 743ea8c036cb..2f51dd1c0146 100644
--- a/reference/random/random/randomizer/getbytesfromstring.xml
+++ b/reference/random/random/randomizer/getbytesfromstring.xml
@@ -13,11 +13,14 @@
    <methodparam><type>int</type><parameter>length</parameter></methodparam>
   </methodsynopsis>
   <para>
-
+   Generates a string containing uniformly selected random bytes from the
+   input <parameter>string</parameter> with the requested <parameter>length</parameter>.
+  </para>
+  <para>
+   The chance for a byte to be selected is proportional to its share
+   of the input <parameter>string</parameter>. If each byte occurs
+   the same amount of times, each byte is equally likely to be selected.
   </para>
-
-  &warn.undocumented.func;
-
  </refsect1>
 
  <refsect1 role="parameters">
@@ -28,7 +31,7 @@
      <term><parameter>string</parameter></term>
      <listitem>
       <para>
-       The string from which the returned bytes are selected.
+       The &string; from which the returned bytes are selected.
       </para>
      </listitem>
     </varlistentry>
@@ -36,7 +39,7 @@
      <term><parameter>length</parameter></term>
      <listitem>
       <para>
-       The length of the random string that should be returned in bytes; must be <literal>1</literal> or greater.
+       The length of the random &string; that should be returned in bytes; must be <literal>1</literal> or greater.
       </para>
      </listitem>
     </varlistentry>
@@ -47,7 +50,7 @@
  <refsect1 role="returnvalues">
   &reftitle.returnvalues;
   <para>
-   Description
+   A &string; containing the requested number of random bytes taken from the input <parameter>string</parameter>.
   </para>
  </refsect1>
 
@@ -72,22 +75,45 @@
 
  <refsect1 role="examples">
   &reftitle.examples;
-  <example xml:id="random-randomizer.getbytesfromstring.example.basic">
+  <example>
    <title><methodname>Random\Randomizer::getBytesFromString</methodname> example</title>
-   <para>
-    Description.
-   </para>
    <programlisting role="php">
 <![CDATA[
 <?php
-echo "Code example";
+$randomizer = new \Random\Randomizer();
+
+printf(
+    "%s.example.com",
+    $randomizer->getBytesFromString('abcdefghijklmnopqrstuvwxyz0123456789', 16)
+);
+?>
+]]>
+   </programlisting>
+   &example.outputs.similar;
+   <screen>
+<![CDATA[
+3zsw04eiubcf82jd.example.com
+]]>
+   </screen>
+  </example>
+
+  <example>
+   <title>Generate a random code for multi-factor authentication</title>
+   <programlisting role="php">
+<![CDATA[
+<?php
+// The Secure engine is the default, but we make it explicit, because
+// multi-factor codes are security sensitive.
+$randomizer = new \Random\Randomizer(new \Random\Engine\Secure());
+
+echo implode('-', str_split($randomizer->getBytesFromString('0123456789', 20), 5));
 ?>
 ]]>
    </programlisting>
-   &example.outputs;
+   &example.outputs.similar;
    <screen>
 <![CDATA[
-Code example
+11551-80418-27047-42075
 ]]>
    </screen>
   </example>