diff --git a/content/posts/2019-02.md b/content/posts/2019-02.md
index 485057536..720690c42 100644
--- a/content/posts/2019-02.md
+++ b/content/posts/2019-02.md
@@ -1020,11 +1020,12 @@ $ ./agrovoc-lookup.py -l fr -i /tmp/top-1500-subjects.txt -om /tmp/matched-subje
 $ cat /tmp/matched-subjects-* | sort | uniq > /tmp/2019-02-21-matched-subjects.txt
 ```
 
-- And then a list of all the unique *unmatched* terms using some utility I've never heard of before called `comm`:
+- And then a list of all the unique *unmatched* terms using some utility I've never heard of before called `comm` or with `diff`:
 
 ```
 $ sort /tmp/top-1500-subjects.txt > /tmp/subjects-sorted.txt
 $ comm -13 /tmp/2019-02-21-matched-subjects.txt /tmp/subjects-sorted.txt > /tmp/2019-02-21-unmatched-subjects.txt
+$ diff --new-line-format="" --unchanged-line-format="" /tmp/subjects-sorted.txt /tmp/2019-02-21-matched-subjects.txt > /tmp/2019-02-21-unmatched-subjects.txt
 ```
 
 - Generate a list of countries and regions from CGSpace for Sisay to look through:
diff --git a/docs/2019-02/index.html b/docs/2019-02/index.html
index fa7b56b33..e6155a19d 100644
--- a/docs/2019-02/index.html
+++ b/docs/2019-02/index.html
@@ -42,7 +42,7 @@ sys     0m1.979s
 <meta property="og:type" content="article" />
 <meta property="og:url" content="https://alanorth.github.io/cgspace-notes/2019-02/" />
 <meta property="article:published_time" content="2019-02-01T21:37:30&#43;02:00"/>
-<meta property="article:modified_time" content="2019-02-20T18:20:09-08:00"/>
+<meta property="article:modified_time" content="2019-02-21T10:08:18-08:00"/>
 
 <meta name="twitter:card" content="summary"/>
 <meta name="twitter:title" content="February, 2019"/>
@@ -89,9 +89,9 @@ sys     0m1.979s
   "@type": "BlogPosting",
   "headline": "February, 2019",
   "url": "https://alanorth.github.io/cgspace-notes/2019-02/",
-  "wordCount": "5947",
+  "wordCount": "5958",
   "datePublished": "2019-02-01T21:37:30&#43;02:00",
-  "dateModified": "2019-02-20T18:20:09-08:00",
+  "dateModified": "2019-02-21T10:08:18-08:00",
   "author": {
     "@type": "Person",
     "name": "Alan Orth"
@@ -1315,11 +1315,12 @@ $ ./agrovoc-lookup.py -l fr -i /tmp/top-1500-subjects.txt -om /tmp/matched-subje
 </code></pre>
 
 <ul>
-<li>And then a list of all the unique <em>unmatched</em> terms using some utility I&rsquo;ve never heard of before called <code>comm</code>:</li>
+<li>And then a list of all the unique <em>unmatched</em> terms using some utility I&rsquo;ve never heard of before called <code>comm</code> or with <code>diff</code>:</li>
 </ul>
 
 <pre><code>$ sort /tmp/top-1500-subjects.txt &gt; /tmp/subjects-sorted.txt
 $ comm -13 /tmp/2019-02-21-matched-subjects.txt /tmp/subjects-sorted.txt &gt; /tmp/2019-02-21-unmatched-subjects.txt
+$ diff --new-line-format=&quot;&quot; --unchanged-line-format=&quot;&quot; /tmp/subjects-sorted.txt /tmp/2019-02-21-matched-subjects.txt &gt; /tmp/2019-02-21-unmatched-subjects.txt
 </code></pre>
 
 <ul>
diff --git a/docs/sitemap.xml b/docs/sitemap.xml
index f10a2b06a..e7d686a78 100644
--- a/docs/sitemap.xml
+++ b/docs/sitemap.xml
@@ -4,7 +4,7 @@
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/2019-02/</loc>
-    <lastmod>2019-02-20T18:20:09-08:00</lastmod>
+    <lastmod>2019-02-21T10:08:18-08:00</lastmod>
   </url>
   
   <url>
@@ -209,7 +209,7 @@
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/</loc>
-    <lastmod>2019-02-20T18:20:09-08:00</lastmod>
+    <lastmod>2019-02-21T10:08:18-08:00</lastmod>
     <priority>0</priority>
   </url>
   
@@ -220,7 +220,7 @@
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/tags/notes/</loc>
-    <lastmod>2019-02-20T18:20:09-08:00</lastmod>
+    <lastmod>2019-02-21T10:08:18-08:00</lastmod>
     <priority>0</priority>
   </url>
   
@@ -232,13 +232,13 @@
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/posts/</loc>
-    <lastmod>2019-02-20T18:20:09-08:00</lastmod>
+    <lastmod>2019-02-21T10:08:18-08:00</lastmod>
     <priority>0</priority>
   </url>
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/tags/</loc>
-    <lastmod>2019-02-20T18:20:09-08:00</lastmod>
+    <lastmod>2019-02-21T10:08:18-08:00</lastmod>
     <priority>0</priority>
   </url>