diff --git a/examples/sample-article/sample-article.xml b/examples/sample-article/sample-article.xml
index 2d5012e48..8b69e0ec5 100644
--- a/examples/sample-article/sample-article.xml
+++ b/examples/sample-article/sample-article.xml
@@ -197,6 +197,11 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
         <!-- use of the translation, "external/"                 -->
         <directories data="numerical"/>
 
+        <!-- A blurb that briefly describes the document -->
+        <blurb>
+            This is a simple string (no markup is allowed) that describes
+            this document, a sample article for the PreTeXt markup language.
+        </blurb>
     </docinfo>
 
     <!--
diff --git a/xsl/pretext-common.xsl b/xsl/pretext-common.xsl
index 010852e57..f168e3ae4 100644
--- a/xsl/pretext-common.xsl
+++ b/xsl/pretext-common.xsl
@@ -2689,6 +2689,17 @@ Book (with parts), "section" at level 3
     </xsl:choose>
 </xsl:template>
 
+<!-- Plain subtitle: used for HTML <meta> tags -->
+<xsl:template match="*" mode="subtitle-plain">
+    <xsl:choose>
+        <xsl:when test="subtitle">
+            <xsl:apply-templates select="subtitle/node()[not(self::fn)]" mode="plain-title-edit"/>
+        </xsl:when>
+        <!-- just empty if there is no subtitles, no default -->
+        <xsl:otherwise/>
+    </xsl:choose>
+</xsl:template>
+
 <!-- We do not wrap an "m" element as part of a plain title -->
 <!-- This will misbehave for m/xref and m/fillin, etc, but  -->
 <!-- these devices should not be in a title anyway          -->
diff --git a/xsl/pretext-html.xsl b/xsl/pretext-html.xsl
index 467ca7a15..c299f5c84 100644
--- a/xsl/pretext-html.xsl
+++ b/xsl/pretext-html.xsl
@@ -454,7 +454,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
                 <meta http-equiv="refresh" content="0; URL='{$html-index-page}'" />
                 <!-- Add a canonical link here, in generic build case? -->
                 <!-- more "meta" elements for discovery -->
-                <xsl:call-template name="open-graph-info"/>
+                <xsl:call-template name="social-meta-info"/>
             </head>
             <!-- body is non-existent, i.e. empty -->
             <body/>
@@ -11146,7 +11146,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
     <xsl:call-template name="keywords-meta-element"/>
     <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
     <!-- more "meta" elements for discovery -->
-    <xsl:call-template name="open-graph-info"/>
+    <xsl:call-template name="social-meta-info"/>
     <xsl:call-template name="pretext-js"/>
     <xsl:call-template name="runestone-header"/>
     <xsl:call-template name="diagcess-header"/>
@@ -11464,18 +11464,19 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
 </xsl:template>
 
 
-<!-- Open Graph Protocol, advertise to Facebook, others       -->
+<!-- Social meta tags (OpenGraph/Facebook, Twitter/X, others) -->
 <!-- https://ogp.me/                                          -->
 <!-- https://developers.facebook.com/docs/sharing/webmasters/ -->
 <!-- https://webcode.tools/generators/open-graph/book         -->
 <!-- Sanity-check live instance: https://opengraphcheck.com/  -->
+<!-- Includes Twitter/X: https://www.digitalocean.com/community/tutorials/how-to-add-twitter-card-and-open-graph-social-metadata-to-your-webpage-with-html -->
 <!-- NB not used for EPUB nor Jupyter (could be in RevealJS?) -->
 
-<xsl:template name="open-graph-info">
-    <!-- og:type - book, article, or missing -->
+<xsl:template name="social-meta-info">
+    <!-- type (og) - book, article, or missing -->
     <xsl:if test="$b-is-article or $b-is-book">
-        <xsl:call-template name="open-graph-meta-element">
-            <xsl:with-param name="namespace" select="'og'"/>
+        <xsl:call-template name="social-meta-element">
+            <xsl:with-param name="og" select="'yes'"/>
             <xsl:with-param name="property" select="'type'"/>
             <xsl:with-param name="content">
                 <xsl:choose>
@@ -11489,10 +11490,11 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             </xsl:with-param>
         </xsl:call-template>
     </xsl:if>
-    <!-- og:image - if it's URL can be constructed -->
+    <!-- image (og,twitter) - if its URL can be constructed -->
     <xsl:if test="$b-has-baseurl and $docinfo/brandlogo">
-        <xsl:call-template name="open-graph-meta-element">
-            <xsl:with-param name="namespace" select="'og'"/>
+        <xsl:call-template name="social-meta-element">
+            <xsl:with-param name="og" select="'yes'"/>
+            <xsl:with-param name="twitter" select="'yes'"/>
             <xsl:with-param name="property" select="'image'"/>
             <!-- URL = baseurl + external + @source -->
             <xsl:with-param name="content">
@@ -11502,48 +11504,104 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
                 <xsl:value-of select="$docinfo/brandlogo/@source"/>
             </xsl:with-param>
         </xsl:call-template>
-    </xsl:if>
-    <!--  -->
-    <!-- book:title (always exactly one)-->
-    <xsl:if test="$b-is-book">
-        <xsl:call-template name="open-graph-meta-element">
-            <xsl:with-param name="namespace" select="'book'"/>
-            <xsl:with-param name="property" select="'title'"/>
+        <!-- alttext -->
+        <xsl:call-template name="social-meta-element">
+            <xsl:with-param name="og" select="'yes'"/>
+            <xsl:with-param name="twitter" select="'yes'"/>
+            <xsl:with-param name="property" select="'image:alt'"/>
             <xsl:with-param name="content">
-                <xsl:apply-templates select="$document-root" mode="title-plain"/>
+                <xsl:text>Document Logo</xsl:text>
             </xsl:with-param>
         </xsl:call-template>
     </xsl:if>
-    <!--  -->
-    <!-- book:author (allow for multiple) -->
-    <xsl:if test="$b-is-book">
-        <xsl:for-each select="$bibinfo/author">
-            <xsl:call-template name="open-graph-meta-element">
-                <xsl:with-param name="namespace" select="'book'"/>
-                <xsl:with-param name="property" select="'author'"/>
-                <xsl:with-param name="content">
-                    <xsl:value-of select="personname"/>
-                </xsl:with-param>
-            </xsl:call-template>
-        </xsl:for-each>
+    <!-- title (og,twitter,book) (always exactly one)-->
+    <xsl:call-template name="social-meta-element">
+        <xsl:with-param name="og" select="'yes'"/>
+        <xsl:with-param name="twitter" select="'yes'"/>
+        <xsl:with-param name="book" select="$b-is-book"/>
+        <xsl:with-param name="property" select="'title'"/>
+        <xsl:with-param name="content">
+            <xsl:apply-templates select="$document-root" mode="title-plain"/>
+            <xsl:if test="$docinfo/blurb and $document-root/subtitle">
+                <xsl:text>: </xsl:text>
+                <xsl:apply-templates select="$document-root" mode="subtitle-plain"/>
+            </xsl:if>
+        </xsl:with-param>
+    </xsl:call-template>
+    <!-- description (og,twitter) -->
+    <xsl:if test="$docinfo/blurb or $document-root/subtitle">
+        <xsl:call-template name="social-meta-element">
+            <xsl:with-param name="og" select="'yes'"/>
+            <xsl:with-param name="twitter" select="'yes'"/>
+            <xsl:with-param name="property" select="'description'"/>
+            <xsl:with-param name="content">
+                <xsl:choose>
+                    <xsl:when test="$docinfo/blurb">
+                        <xsl:value-of select="normalize-space($docinfo/blurb)"/>
+                    </xsl:when>
+                    <xsl:otherwise>
+                        <xsl:apply-templates select="$document-root" mode="subtitle-plain"/>
+                    </xsl:otherwise>
+                </xsl:choose>
+            </xsl:with-param>
+        </xsl:call-template>
     </xsl:if>
-    <!--  -->
+    <!-- card (twitter) -->
+    <xsl:call-template name="social-meta-element">
+        <xsl:with-param name="twitter" select="'yes'"/>
+        <xsl:with-param name="property" select="'card'"/>
+        <xsl:with-param name="content">
+            <xsl:choose>
+                <xsl:when test="$b-has-baseurl and $docinfo/brandlogo">
+                    <xsl:text>summary_large_image</xsl:text>
+                </xsl:when>
+                <xsl:otherwise>
+                    <xsl:text>summary</xsl:text>
+                </xsl:otherwise>
+            </xsl:choose>
+        </xsl:with-param>
+    </xsl:call-template>
 </xsl:template>
 
-<xsl:template name="open-graph-meta-element">
-    <xsl:param name="namespace"/>
+<xsl:template name="social-meta-element">
+    <xsl:param name="twitter"/>
+    <xsl:param name="og"/>
+    <xsl:param name="book"/>
     <xsl:param name="property"/>
     <xsl:param name="content"/>
-    <meta>
-        <xsl:attribute name="property">
-            <xsl:value-of select="$namespace"/>
-            <xsl:text>:</xsl:text>
-            <xsl:value-of select="$property"/>
-        </xsl:attribute>
-        <xsl:attribute name="content">
-            <xsl:value-of select="$content"/>
-        </xsl:attribute>
-    </meta>
+    <xsl:if test="$twitter">
+        <meta>
+            <xsl:attribute name="name">
+                <xsl:text>twitter:</xsl:text>
+                <xsl:value-of select="$property"/>
+            </xsl:attribute>
+            <xsl:attribute name="content">
+                <xsl:value-of select="$content"/>
+            </xsl:attribute>
+        </meta>
+    </xsl:if>
+    <xsl:if test="$og">
+        <meta>
+            <xsl:attribute name="property">
+                <xsl:text>og:</xsl:text>
+                <xsl:value-of select="$property"/>
+            </xsl:attribute>
+            <xsl:attribute name="content">
+                <xsl:value-of select="$content"/>
+            </xsl:attribute>
+        </meta>
+    </xsl:if>
+    <xsl:if test="$book">
+        <meta>
+            <xsl:attribute name="property">
+                <xsl:text>book:</xsl:text>
+                <xsl:value-of select="$property"/>
+            </xsl:attribute>
+            <xsl:attribute name="content">
+                <xsl:value-of select="$content"/>
+            </xsl:attribute>
+        </meta>
+    </xsl:if>
 </xsl:template>