diff --git a/lab000-important-terms.xml b/lab000-important-terms.xml
index 708dd426..df1c8f40 100644
--- a/lab000-important-terms.xml
+++ b/lab000-important-terms.xml
@@ -8,7 +8,7 @@
 <title>Host Operating System (Host)</title>
 <para>The operating system that is installed on your laptop or
 desktop that hosts virtual machines. Commonly referred to as
- <firstterm>host OS</firstterm> or <firstterm>host</firstterm>.
+ <glossterm>host OS</glossterm> or <glossterm>host</glossterm>.
 In short, the machine where your Virtual Box is
 installed.</para>
 </formalpara>
@@ -16,8 +16,8 @@
 <title>Guest Operating System (Guest)</title>
 <para>The operating system that is installed on your Virtual Box
 Virtual Machine. This virtual instance is independent of the
- host OS. Commonly referred to as <firstterm>guest OS</firstterm>
- or <firstterm>guest</firstterm>.</para>
+ host OS. Commonly referred to as <glossterm>guest OS</glossterm>
+ or <glossterm>guest</glossterm>.</para>
 </formalpara>
 <formalpara>
 <title>Node</title>
</div><div class="naked_ctrl">
<form action="/index.cgi/contrast" method="get" name="gate">
<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="https://opendev.org/openstack/training-guides/commit/ca4a4bd02eaff420546ec0bb13bc85a50a8626e8.diff">(-&gt;オリジナル)</a>
/ <label>アドレス: <input type="text" name="naked_post_url" value="https://opendev.org/openstack/training-guides/commit/ca4a4bd02eaff420546ec0bb13bc85a50a8626e8.diff" size="22" /></label> <label>モード: <select name="naked_post_mode">
<option value="default">デフォルト</option>
<option value="speech">音声ブラウザ</option>
<option value="ruby">ルビ付き</option>
<option value="contrast" selected="selected">配色反転</option>
<option value="larger-text">文字拡大</option>
<option value="mobile">モバイル</option>
</select>
<input type="submit" value="表示" />
</p>
</form>
</div>