From 7ce788f4515d0e48f20c0814b40ab3f217f17414 Mon Sep 17 00:00:00 2001
From: Steven Clontz <steven.clontz@gmail.com>
Date: Tue, 7 Apr 2026 12:15:40 -0500
Subject: [PATCH 1/8] first pass at social metas

---
 xsl/pretext-html.xsl | 126 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 107 insertions(+), 19 deletions(-)

diff --git a/xsl/pretext-html.xsl b/xsl/pretext-html.xsl
index 467ca7a15..4d721ec89 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"/>
@@ -11464,17 +11464,18 @@ 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 $b-is-book">
-        <xsl:call-template name="open-graph-meta-element">
+        <xsl:call-template name="social-meta-element">
             <xsl:with-param name="namespace" select="'og'"/>
             <xsl:with-param name="property" select="'type'"/>
             <xsl:with-param name="content">
@@ -11489,9 +11490,10 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             </xsl:with-param>
         </xsl:call-template>
     </xsl:if>
-    <!-- og:image - if it's URL can be constructed -->
+    <!--  -->
+    <!-- image (og,twitter) - if its URL can be constructed -->
     <xsl:if test="$b-has-baseurl and $docinfo/brandlogo">
-        <xsl:call-template name="open-graph-meta-element">
+        <xsl:call-template name="social-meta-element">
             <xsl:with-param name="namespace" select="'og'"/>
             <xsl:with-param name="property" select="'image'"/>
             <!-- URL = baseurl + external + @source -->
@@ -11502,23 +11504,79 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
                 <xsl:value-of select="$docinfo/brandlogo/@source"/>
             </xsl:with-param>
         </xsl:call-template>
+        <xsl:call-template name="social-meta-element">
+            <xsl:with-param name="namespace" select="'twitter'"/>
+            <xsl:with-param name="name" select="'image'"/>
+            <!-- URL = baseurl + external + @source -->
+            <xsl:with-param name="content">
+                <!-- empty when not using managed directories -->
+                <xsl:value-of select="$baseurl"/>
+                <xsl:value-of select="$external-directory"/>
+                <xsl:value-of select="$docinfo/brandlogo/@source"/>
+            </xsl:with-param>
+        </xsl:call-template>
+        <!-- alttext -->
+        <xsl:call-template name="social-meta-element">
+            <xsl:with-param name="namespace" select="'og'"/>
+            <xsl:with-param name="property" select="'image:alt'"/>
+            <xsl:with-param name="content">
+                <xsl:text>Document Logo</xsl:text>
+            </xsl:with-param>
+        </xsl:call-template>
+        <xsl:call-template name="social-meta-element">
+            <xsl:with-param name="namespace" select="'twitter'"/>
+            <xsl:with-param name="name" select="'image:alt'"/>
+            <xsl:with-param name="content">
+                <xsl:text>Document Logo</xsl:text>
+            </xsl:with-param>
+        </xsl:call-template>
     </xsl:if>
     <!--  -->
-    <!-- book:title (always exactly one)-->
+    <!-- title (og,twitter,book) (always exactly one)-->
+    <xsl:call-template name="social-meta-element">
+        <xsl:with-param name="namespace" select="'og'"/>
+        <xsl:with-param name="property" select="'title'"/>
+        <xsl:with-param name="content">
+            <xsl:apply-templates select="$document-root" mode="title-full"/>
+        </xsl:with-param>
+    </xsl:call-template>
+    <xsl:call-template name="social-meta-element">
+        <xsl:with-param name="namespace" select="'twitter'"/>
+        <xsl:with-param name="name" select="'title'"/>
+        <xsl:with-param name="content">
+            <xsl:apply-templates select="$document-root" mode="title-full"/>
+        </xsl:with-param>
+    </xsl:call-template>
     <xsl:if test="$b-is-book">
-        <xsl:call-template name="open-graph-meta-element">
+        <xsl:call-template name="social-meta-element">
             <xsl:with-param name="namespace" select="'book'"/>
             <xsl:with-param name="property" select="'title'"/>
             <xsl:with-param name="content">
-                <xsl:apply-templates select="$document-root" mode="title-plain"/>
+                <xsl:apply-templates select="$document-root" mode="title-full"/>
             </xsl:with-param>
         </xsl:call-template>
     </xsl:if>
     <!--  -->
-    <!-- book:author (allow for multiple) -->
+    <!-- description (og,twitter) -->
+    <xsl:call-template name="social-meta-element">
+        <xsl:with-param name="namespace" select="'og'"/>
+        <xsl:with-param name="property" select="'description'"/>
+        <xsl:with-param name="content">
+            <xsl:value-of select="$docinfo/blurb"/>
+        </xsl:with-param>
+    </xsl:call-template>
+    <xsl:call-template name="social-meta-element">
+        <xsl:with-param name="namespace" select="'twitter'"/>
+        <xsl:with-param name="name" select="'description'"/>
+        <xsl:with-param name="content">
+            <xsl:value-of select="$docinfo/blurb"/>
+        </xsl:with-param>
+    </xsl:call-template>
+    <!--  -->
+    <!-- author (book) (allow for multiple) -->
     <xsl:if test="$b-is-book">
         <xsl:for-each select="$bibinfo/author">
-            <xsl:call-template name="open-graph-meta-element">
+            <xsl:call-template name="social-meta-element">
                 <xsl:with-param name="namespace" select="'book'"/>
                 <xsl:with-param name="property" select="'author'"/>
                 <xsl:with-param name="content">
@@ -11527,19 +11585,49 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             </xsl:call-template>
         </xsl:for-each>
     </xsl:if>
+    <xsl:if test="$b-is-article">
+        <xsl:for-each select="$bibinfo/author">
+            <xsl:call-template name="social-meta-element">
+                <xsl:with-param name="namespace" select="'article'"/>
+                <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>
+    </xsl:if>
+    <!--  -->
+    <!-- card (twitter) -->
+    <xsl:call-template name="social-meta-element">
+        <xsl:with-param name="namespace" select="'twitter'"/>
+        <xsl:with-param name="name" select="'card'"/>
+        <xsl:with-param name="content">
+            <xsl:text>summary_large_image</xsl:text>
+        </xsl:with-param>
+    </xsl:call-template>
     <!--  -->
 </xsl:template>
 
-<xsl:template name="open-graph-meta-element">
+<xsl:template name="social-meta-element">
     <xsl:param name="namespace"/>
     <xsl:param name="property"/>
+    <xsl:param name="name"/>
     <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:if select="$property">
+            <xsl:attribute name="property">
+                <xsl:value-of select="$namespace"/>
+                <xsl:text>:</xsl:text>
+                <xsl:value-of select="$property"/>
+            </xsl:attribute>
+        </xsl:if>
+        <xsl:if select="$name">
+            <xsl:attribute name="name">
+                <xsl:value-of select="$namespace"/>
+                <xsl:text>:</xsl:text>
+                <xsl:value-of select="$name"/>
+            </xsl:attribute>
+        </xsl:if>
         <xsl:attribute name="content">
             <xsl:value-of select="$content"/>
         </xsl:attribute>

From 857c31120d4855fdce4e475db11bb94ead4377c1 Mon Sep 17 00:00:00 2001
From: Steven Clontz <steven.clontz@gmail.com>
Date: Tue, 7 Apr 2026 19:15:52 +0000
Subject: [PATCH 2/8] fix xsl:if

---
 xsl/pretext-html.xsl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xsl/pretext-html.xsl b/xsl/pretext-html.xsl
index 4d721ec89..6d2102647 100644
--- a/xsl/pretext-html.xsl
+++ b/xsl/pretext-html.xsl
@@ -11614,14 +11614,14 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
     <xsl:param name="name"/>
     <xsl:param name="content"/>
     <meta>
-        <xsl:if select="$property">
+        <xsl:if test="$property">
             <xsl:attribute name="property">
                 <xsl:value-of select="$namespace"/>
                 <xsl:text>:</xsl:text>
                 <xsl:value-of select="$property"/>
             </xsl:attribute>
         </xsl:if>
-        <xsl:if select="$name">
+        <xsl:if test="$name">
             <xsl:attribute name="name">
                 <xsl:value-of select="$namespace"/>
                 <xsl:text>:</xsl:text>

From baf880beaebf2cbc960c69c4d441c329afa246fc Mon Sep 17 00:00:00 2001
From: Steven Clontz <steven.clontz@gmail.com>
Date: Tue, 7 Apr 2026 19:28:01 +0000
Subject: [PATCH 3/8] use subtitle as backup description, normalize spacing for
 blurb

---
 xsl/pretext-html.xsl | 44 ++++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/xsl/pretext-html.xsl b/xsl/pretext-html.xsl
index 6d2102647..ab3b4949a 100644
--- a/xsl/pretext-html.xsl
+++ b/xsl/pretext-html.xsl
@@ -11558,20 +11558,36 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
     </xsl:if>
     <!--  -->
     <!-- description (og,twitter) -->
-    <xsl:call-template name="social-meta-element">
-        <xsl:with-param name="namespace" select="'og'"/>
-        <xsl:with-param name="property" select="'description'"/>
-        <xsl:with-param name="content">
-            <xsl:value-of select="$docinfo/blurb"/>
-        </xsl:with-param>
-    </xsl:call-template>
-    <xsl:call-template name="social-meta-element">
-        <xsl:with-param name="namespace" select="'twitter'"/>
-        <xsl:with-param name="name" select="'description'"/>
-        <xsl:with-param name="content">
-            <xsl:value-of select="$docinfo/blurb"/>
-        </xsl:with-param>
-    </xsl:call-template>
+    <xsl:if test="$docinfo/blurb or $document-root/subtitle">
+        <xsl:call-template name="social-meta-element">
+            <xsl:with-param name="namespace" select="'og'"/>
+            <xsl:with-param name="property" select="'description'"/>
+            <xsl:with-param name="content">
+                <xsl:choose>
+                    <xsl:when test="$docinfo/blurb">
+                        <xsl:value-of select="normalize-space($docinfo/blurb)"/>
+                    </xsl:when>
+                    <xsl:otherwise>
+                        <xsl:value-of select="$document-root/subtitle"/>
+                    </xsl:otherwise>
+                </xsl:choose>
+            </xsl:with-param>
+        </xsl:call-template>
+        <xsl:call-template name="social-meta-element">
+            <xsl:with-param name="namespace" select="'twitter'"/>
+            <xsl:with-param name="name" 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:value-of select="$document-root/subtitle"/>
+                    </xsl:otherwise>
+                </xsl:choose>
+            </xsl:with-param>
+        </xsl:call-template>
+    </xsl:if>
     <!--  -->
     <!-- author (book) (allow for multiple) -->
     <xsl:if test="$b-is-book">

From f8b92762e35bd9c18a8c8bcdca946f54016a83dc Mon Sep 17 00:00:00 2001
From: Steven Clontz <steven.clontz@gmail.com>
Date: Tue, 7 Apr 2026 19:32:52 +0000
Subject: [PATCH 4/8] revert to title-plain, add subtitle if blurb exists

---
 xsl/pretext-html.xsl | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/xsl/pretext-html.xsl b/xsl/pretext-html.xsl
index ab3b4949a..86acc01ce 100644
--- a/xsl/pretext-html.xsl
+++ b/xsl/pretext-html.xsl
@@ -11537,14 +11537,22 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
         <xsl:with-param name="namespace" select="'og'"/>
         <xsl:with-param name="property" select="'title'"/>
         <xsl:with-param name="content">
-            <xsl:apply-templates select="$document-root" mode="title-full"/>
+            <xsl:apply-templates select="$document-root" mode="title-plain"/>
+            <xsl:if test="$docinfo/blurb and $document-root/subtitle">
+                <xsl:text>: </xsl:text>
+                <xsl:value-of select="$document-root/subtitle"/>
+            </xsl:if>
         </xsl:with-param>
     </xsl:call-template>
     <xsl:call-template name="social-meta-element">
         <xsl:with-param name="namespace" select="'twitter'"/>
         <xsl:with-param name="name" select="'title'"/>
         <xsl:with-param name="content">
-            <xsl:apply-templates select="$document-root" mode="title-full"/>
+            <xsl:apply-templates select="$document-root" mode="title-plain"/>
+            <xsl:if test="$docinfo/blurb and $document-root/subtitle">
+                <xsl:text>: </xsl:text>
+                <xsl:value-of select="$document-root/subtitle"/>
+            </xsl:if>
         </xsl:with-param>
     </xsl:call-template>
     <xsl:if test="$b-is-book">
@@ -11552,7 +11560,11 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             <xsl:with-param name="namespace" select="'book'"/>
             <xsl:with-param name="property" select="'title'"/>
             <xsl:with-param name="content">
-                <xsl:apply-templates select="$document-root" mode="title-full"/>
+                <xsl:apply-templates select="$document-root" mode="title-plain"/>
+                <xsl:if test="$docinfo/blurb and $document-root/subtitle">
+                    <xsl:text>: </xsl:text>
+                    <xsl:value-of select="$document-root/subtitle"/>
+                </xsl:if>
             </xsl:with-param>
         </xsl:call-template>
     </xsl:if>

From 4e7b6b056627740e4f1c725e6d32d02cc1965a37 Mon Sep 17 00:00:00 2001
From: Steven Clontz <steven.clontz@gmail.com>
Date: Tue, 7 Apr 2026 19:34:46 +0000
Subject: [PATCH 5/8] add blurb to sample-article

---
 examples/sample-article/sample-article.xml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/examples/sample-article/sample-article.xml b/examples/sample-article/sample-article.xml
index 2d5012e48..0c3450b23 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 for describing  -->
+        <blurb>
+            This is a simple string (no markup is allowed) that describes
+            this document, a sample article for the PreTeXt markup language.
+        </blurb>
     </docinfo>
 
     <!--

From fda1db06e7d1c2129a38cf92a895b99cb4dbceae Mon Sep 17 00:00:00 2001
From: Steven Clontz <steven.clontz@gmail.com>
Date: Tue, 7 Apr 2026 19:44:57 +0000
Subject: [PATCH 6/8] use subtitle template instead of value-of

---
 xsl/pretext-html.xsl | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/xsl/pretext-html.xsl b/xsl/pretext-html.xsl
index 86acc01ce..66cbe4a49 100644
--- a/xsl/pretext-html.xsl
+++ b/xsl/pretext-html.xsl
@@ -11540,7 +11540,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             <xsl:apply-templates select="$document-root" mode="title-plain"/>
             <xsl:if test="$docinfo/blurb and $document-root/subtitle">
                 <xsl:text>: </xsl:text>
-                <xsl:value-of select="$document-root/subtitle"/>
+                <xsl:apply-templates select="$document-root" mode="subtitle" />
             </xsl:if>
         </xsl:with-param>
     </xsl:call-template>
@@ -11551,7 +11551,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             <xsl:apply-templates select="$document-root" mode="title-plain"/>
             <xsl:if test="$docinfo/blurb and $document-root/subtitle">
                 <xsl:text>: </xsl:text>
-                <xsl:value-of select="$document-root/subtitle"/>
+                <xsl:apply-templates select="$document-root" mode="subtitle" />
             </xsl:if>
         </xsl:with-param>
     </xsl:call-template>
@@ -11563,7 +11563,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
                 <xsl:apply-templates select="$document-root" mode="title-plain"/>
                 <xsl:if test="$docinfo/blurb and $document-root/subtitle">
                     <xsl:text>: </xsl:text>
-                    <xsl:value-of select="$document-root/subtitle"/>
+                    <xsl:apply-templates select="$document-root" mode="subtitle" />
                 </xsl:if>
             </xsl:with-param>
         </xsl:call-template>
@@ -11580,7 +11580,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
                         <xsl:value-of select="normalize-space($docinfo/blurb)"/>
                     </xsl:when>
                     <xsl:otherwise>
-                        <xsl:value-of select="$document-root/subtitle"/>
+                        <xsl:apply-templates select="$document-root" mode="subtitle" />
                     </xsl:otherwise>
                 </xsl:choose>
             </xsl:with-param>
@@ -11594,7 +11594,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
                         <xsl:value-of select="normalize-space($docinfo/blurb)"/>
                     </xsl:when>
                     <xsl:otherwise>
-                        <xsl:value-of select="$document-root/subtitle"/>
+                        <xsl:apply-templates select="$document-root" mode="subtitle" />
                     </xsl:otherwise>
                 </xsl:choose>
             </xsl:with-param>

From e0dab2c521e1d5db1379b7971bd4733a3ca156be Mon Sep 17 00:00:00 2001
From: Steven Clontz <steven.clontz@gmail.com>
Date: Tue, 7 Apr 2026 19:50:52 +0000
Subject: [PATCH 7/8] finish comment in sample article

---
 examples/sample-article/sample-article.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/sample-article/sample-article.xml b/examples/sample-article/sample-article.xml
index 0c3450b23..8b69e0ec5 100644
--- a/examples/sample-article/sample-article.xml
+++ b/examples/sample-article/sample-article.xml
@@ -197,7 +197,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
         <!-- use of the translation, "external/"                 -->
         <directories data="numerical"/>
 
-        <!-- A blurb for describing  -->
+        <!-- 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.

From b867072143c9aad233917367b9c565ef0186e4ff Mon Sep 17 00:00:00 2001
From: Steven Clontz <steven.clontz@gmail.com>
Date: Mon, 13 Apr 2026 15:52:04 +0000
Subject: [PATCH 8/8] DRY up code, fix twitter card type when no image exists

---
 xsl/pretext-html.xsl | 162 ++++++++++++++-----------------------------
 1 file changed, 52 insertions(+), 110 deletions(-)

diff --git a/xsl/pretext-html.xsl b/xsl/pretext-html.xsl
index 66cbe4a49..a5b7436ad 100644
--- a/xsl/pretext-html.xsl
+++ b/xsl/pretext-html.xsl
@@ -11476,7 +11476,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
     <!-- type (og) - book, article, or missing -->
     <xsl:if test="$b-is-article or $b-is-book">
         <xsl:call-template name="social-meta-element">
-            <xsl:with-param name="namespace" select="'og'"/>
+            <xsl:with-param name="og" select="'yes'"/>
             <xsl:with-param name="property" select="'type'"/>
             <xsl:with-param name="content">
                 <xsl:choose>
@@ -11490,11 +11490,11 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             </xsl:with-param>
         </xsl:call-template>
     </xsl:if>
-    <!--  -->
     <!-- image (og,twitter) - if its URL can be constructed -->
     <xsl:if test="$b-has-baseurl and $docinfo/brandlogo">
         <xsl:call-template name="social-meta-element">
-            <xsl:with-param name="namespace" select="'og'"/>
+            <xsl:with-param name="og" select="'yes'"/>
+            <xsl:with-param name="twitter" select="'yes'"/>
             <xsl:with-param name="property" select="'image'"/>
             <!-- URL = baseurl + external + @source -->
             <xsl:with-param name="content">
@@ -11504,37 +11504,21 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
                 <xsl:value-of select="$docinfo/brandlogo/@source"/>
             </xsl:with-param>
         </xsl:call-template>
-        <xsl:call-template name="social-meta-element">
-            <xsl:with-param name="namespace" select="'twitter'"/>
-            <xsl:with-param name="name" select="'image'"/>
-            <!-- URL = baseurl + external + @source -->
-            <xsl:with-param name="content">
-                <!-- empty when not using managed directories -->
-                <xsl:value-of select="$baseurl"/>
-                <xsl:value-of select="$external-directory"/>
-                <xsl:value-of select="$docinfo/brandlogo/@source"/>
-            </xsl:with-param>
-        </xsl:call-template>
         <!-- alttext -->
         <xsl:call-template name="social-meta-element">
-            <xsl:with-param name="namespace" select="'og'"/>
+            <xsl:with-param name="og" select="'yes'"/>
+            <xsl:with-param name="twitter" select="'yes'"/>
             <xsl:with-param name="property" select="'image:alt'"/>
             <xsl:with-param name="content">
                 <xsl:text>Document Logo</xsl:text>
             </xsl:with-param>
         </xsl:call-template>
-        <xsl:call-template name="social-meta-element">
-            <xsl:with-param name="namespace" select="'twitter'"/>
-            <xsl:with-param name="name" select="'image:alt'"/>
-            <xsl:with-param name="content">
-                <xsl:text>Document Logo</xsl:text>
-            </xsl:with-param>
-        </xsl:call-template>
     </xsl:if>
-    <!--  -->
     <!-- title (og,twitter,book) (always exactly one)-->
     <xsl:call-template name="social-meta-element">
-        <xsl:with-param name="namespace" select="'og'"/>
+        <xsl:with-param name="og" select="'yes'"/>
+        <xsl:with-param name="twitter" select="'yes'"/>
+        <xsl:with-param name="book" select="$b-is-book"/>
         <xsl:with-param name="property" select="'title'"/>
         <xsl:with-param name="content">
             <xsl:apply-templates select="$document-root" mode="title-plain"/>
@@ -11544,35 +11528,11 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             </xsl:if>
         </xsl:with-param>
     </xsl:call-template>
-    <xsl:call-template name="social-meta-element">
-        <xsl:with-param name="namespace" select="'twitter'"/>
-        <xsl:with-param name="name" select="'title'"/>
-        <xsl:with-param name="content">
-            <xsl:apply-templates select="$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" />
-            </xsl:if>
-        </xsl:with-param>
-    </xsl:call-template>
-    <xsl:if test="$b-is-book">
-        <xsl:call-template name="social-meta-element">
-            <xsl:with-param name="namespace" select="'book'"/>
-            <xsl:with-param name="property" select="'title'"/>
-            <xsl:with-param name="content">
-                <xsl:apply-templates select="$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" />
-                </xsl:if>
-            </xsl:with-param>
-        </xsl:call-template>
-    </xsl:if>
-    <!--  -->
     <!-- description (og,twitter) -->
     <xsl:if test="$docinfo/blurb or $document-root/subtitle">
         <xsl:call-template name="social-meta-element">
-            <xsl:with-param name="namespace" select="'og'"/>
+            <xsl:with-param name="og" select="'yes'"/>
+            <xsl:with-param name="twitter" select="'yes'"/>
             <xsl:with-param name="property" select="'description'"/>
             <xsl:with-param name="content">
                 <xsl:choose>
@@ -11585,81 +11545,63 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
                 </xsl:choose>
             </xsl:with-param>
         </xsl:call-template>
-        <xsl:call-template name="social-meta-element">
-            <xsl:with-param name="namespace" select="'twitter'"/>
-            <xsl:with-param name="name" select="'description'"/>
-            <xsl:with-param name="content">
-                <xsl:choose>
-                    <xsl:when test="$docinfo/blurb">
-                        <xsl:value-of select="normalize-space($docinfo/blurb)"/>
-                    </xsl:when>
-                    <xsl:otherwise>
-                        <xsl:apply-templates select="$document-root" mode="subtitle" />
-                    </xsl:otherwise>
-                </xsl:choose>
-            </xsl:with-param>
-        </xsl:call-template>
-    </xsl:if>
-    <!--  -->
-    <!-- author (book) (allow for multiple) -->
-    <xsl:if test="$b-is-book">
-        <xsl:for-each select="$bibinfo/author">
-            <xsl:call-template name="social-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>
     </xsl:if>
-    <xsl:if test="$b-is-article">
-        <xsl:for-each select="$bibinfo/author">
-            <xsl:call-template name="social-meta-element">
-                <xsl:with-param name="namespace" select="'article'"/>
-                <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>
-    </xsl:if>
-    <!--  -->
     <!-- card (twitter) -->
     <xsl:call-template name="social-meta-element">
-        <xsl:with-param name="namespace" select="'twitter'"/>
-        <xsl:with-param name="name" select="'card'"/>
+        <xsl:with-param name="twitter" select="'yes'"/>
+        <xsl:with-param name="property" select="'card'"/>
         <xsl:with-param name="content">
-            <xsl:text>summary_large_image</xsl:text>
+            <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="social-meta-element">
-    <xsl:param name="namespace"/>
+    <xsl:param name="twitter"/>
+    <xsl:param name="og"/>
+    <xsl:param name="book"/>
     <xsl:param name="property"/>
-    <xsl:param name="name"/>
     <xsl:param name="content"/>
-    <meta>
-        <xsl:if test="$property">
+    <xsl:if test="$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="$og">
+        <meta>
             <xsl:attribute name="property">
-                <xsl:value-of select="$namespace"/>
-                <xsl:text>:</xsl:text>
+                <xsl:text>og:</xsl:text>
                 <xsl:value-of select="$property"/>
             </xsl:attribute>
-        </xsl:if>
-        <xsl:if test="$name">
-            <xsl:attribute name="name">
-                <xsl:value-of select="$namespace"/>
-                <xsl:text>:</xsl:text>
-                <xsl:value-of select="$name"/>
+            <xsl:attribute name="content">
+                <xsl:value-of select="$content"/>
             </xsl:attribute>
-        </xsl:if>
-        <xsl:attribute name="content">
-            <xsl:value-of select="$content"/>
-        </xsl:attribute>
-    </meta>
+        </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>