diff --git a/themes/vocabulary_theme/templates/404.html b/themes/vocabulary_theme/templates/404.html
index b83565c85..57d207304 100644
--- a/themes/vocabulary_theme/templates/404.html
+++ b/themes/vocabulary_theme/templates/404.html
@@ -1,10 +1,10 @@
 {% extends "layout.html" %}
 {% block body %}
-  <div class="container padding-vertical-xxl has-text-centered">
+  <main class="container padding-vertical-xxl has-text-centered">
     <h1>404</h1>
     <h2>Page Not Found!</h2>
     <p class="body-big">Sorry. The page you are looking for doesn't exist.</p>
     <a class="button is-success margin-vertical-big" href="/">Return Home</a>
-  </div>
+  </main>
 <!-- Creative commons -->
 {% endblock %}
diff --git a/themes/vocabulary_theme/templates/author.html b/themes/vocabulary_theme/templates/author.html
index 97e4bab64..b164d3843 100644
--- a/themes/vocabulary_theme/templates/author.html
+++ b/themes/vocabulary_theme/templates/author.html
@@ -12,20 +12,20 @@
       <div class="columns">
         <div class="column is-one-quarter-tablet-only is-2-desktop">
           <figure class="image profile">
-            <img class="profile" src="https://secure.gravatar.com/avatar/{{ this.md5_hashed_email }}?size=200&d=mp" alt="gravatar">
+            <img class="profile" src="https://secure.gravatar.com/avatar/{{ this.md5_hashed_email }}?size=200&d=mp" alt="Gravatar image of {{ render_author_name(this) }}" aria-labelledby="author-name">
           </figure>
         </div>
         <div class="column content is-8">
-          <h2>{{ render_author_name(this) }}</h2>
+          <h2 id="author-name">{{ render_author_name(this) }}</h2>
           {% if this.about %}
-            <div class="about">{{ this.about }}</div>
+            <div class="about" aria-describedby="author-about">{{ this.about }}</div>
           {% endif %}
-          <a class="button small" href="{{ this.parent|url }}">See all authors</a>
+          <a class="button small" href="{{ this.parent|url }}" aria-label="See all authors">{{ this.parent.title }}</a>
         </div>
       </div>
     </div>
   </div>
-  <div class="posts container">
+  <div class="posts container" role="region" aria-labelledby="author-name">
     {{ render_author_posts(this.children) }}
   </div>
 </div>
diff --git a/themes/vocabulary_theme/templates/authors.html b/themes/vocabulary_theme/templates/authors.html
index 40d2360d3..4981cbfcd 100644
--- a/themes/vocabulary_theme/templates/authors.html
+++ b/themes/vocabulary_theme/templates/authors.html
@@ -5,7 +5,8 @@
 {% block title %} Authors {% endblock %}
 
 {% block body %}
-  <div class="all-authors">
+  <div class="all-authors" role="region" aria-labelledby="authors-list">
+    <h2 id="authors-list" class="visually-hidden">List of Authors</h2>
     <div class="header">
       <h1 class="container">Authors</h1>
     </div>
@@ -18,3 +19,4 @@ <h1 class="container">Authors</h1>
     </div>
   </div>
 {% endblock %}
+
diff --git a/themes/vocabulary_theme/templates/blocks/get-involved.html b/themes/vocabulary_theme/templates/blocks/get-involved.html
index 8a9673745..1de4bcefe 100644
--- a/themes/vocabulary_theme/templates/blocks/get-involved.html
+++ b/themes/vocabulary_theme/templates/blocks/get-involved.html
@@ -1,17 +1,20 @@
 <section class="get-involved">
   <div class="container">
     <div class="column is-9 is-paddingless">
-      {{ this.title }}
+      <h2 id="get-involved">{{ this.title }}</h2>
     </div>
 
     <div class="columns get-involved-links">
-      <div class="column is-one-third">
+      <div class="column is-one-third" aria-labelledby="product-links">
+        <h3 id="product-links" class="visually-hidden">Product Links</h3>
         {{ this.links_product }}
       </div>
-      <div class="column is-one-third">
+      <div class="column is-one-third" aria-labelledby="integrate-links">
+        <h3 id="integrate-links" class="visually-hidden">Integrate Links</h3>
         {{ this.links_integrate }}
       </div>
-      <div class="column is-one-third">
+      <div class="column is-one-third" aria-labelledby="plugins-links">
+        <h3 id="plugins-links" class="visually-hidden">Plugins Links</h3>
         {{ this.links_plugins }}
       </div>
     </div>
diff --git a/themes/vocabulary_theme/templates/blocks/hero.html b/themes/vocabulary_theme/templates/blocks/hero.html
index 31358db02..0da854b91 100644
--- a/themes/vocabulary_theme/templates/blocks/hero.html
+++ b/themes/vocabulary_theme/templates/blocks/hero.html
@@ -1,7 +1,7 @@
-<section class="hero">
+<section class="hero" role="region">
   <div class="container">
     <div class="hero-title column is-12 is-paddingless">
-      <h1>
+      <h1 id="hero-title">
         {{ this.title }}
       </h1>
     </div>
diff --git a/themes/vocabulary_theme/templates/blog-categories.html b/themes/vocabulary_theme/templates/blog-categories.html
index 036d6b142..26e9961ff 100644
--- a/themes/vocabulary_theme/templates/blog-categories.html
+++ b/themes/vocabulary_theme/templates/blog-categories.html
@@ -5,9 +5,9 @@
 {% block title %}Categories{% endblock %}
 
 {% block body %}
-  <div class="all-categories">
+  <div class="all-categories" role="region" aria-labelledby="categories-title">
     <div class="header">
-      <h1 class="container">Categories</h1>
+      <h1 id="categories-title" class="container">Categories</h1>
     </div>
     <div class="categories-list container">
       {{ render_categories(this) }}
diff --git a/themes/vocabulary_theme/templates/blog-category.html b/themes/vocabulary_theme/templates/blog-category.html
index c0e4ba844..c50afeb73 100644
--- a/themes/vocabulary_theme/templates/blog-category.html
+++ b/themes/vocabulary_theme/templates/blog-category.html
@@ -5,14 +5,14 @@
 {% block title %}{{ this.name }}{% endblock %}
 
 {% block body %}
-<div class="all-categories">
+<div class="all-categories" aria-labelledby="all-categories-title">
   <div class="header">
     <div class="container">
-      <h1>All posts categorized "{{ this.name }}"</h1>
-      <a class="button small margin-top-bigger" href="{{ this.parent|url }}">See all categories</a>
+      <h1 id="all-categories-title">All posts categorized "{{ this.name }}"</h1>
+      <a class="button small margin-top-bigger" href="{{ this.parent|url }}" aria-label="See all categories">See all categories</a>
     </div>
   </div>
-  <div class="categories-list container">
+  <div class="categories-list container" role="list">
     {{ render_posts(this.children) }}
   </div>
 </div>
diff --git a/themes/vocabulary_theme/templates/blog-post.html b/themes/vocabulary_theme/templates/blog-post.html
index 62f90d126..c312ae9b5 100644
--- a/themes/vocabulary_theme/templates/blog-post.html
+++ b/themes/vocabulary_theme/templates/blog-post.html
@@ -6,14 +6,16 @@
 {% block title %}{{ this.title }}{% endblock %}
 
 {% block body %}
-  <div class="single-post">
+  <div class="single-post" role="article">
     <header class="single-post-header">
       <div class="container">
         <h4>CC Open Source Blog</h4>
-        <h2 class="title">{{ this.title }}</h2>
+        <h2 class="title" id="post-title">{{ this.title }}</h2>
         <div class="author columns is-marginless">
-          {{ render_author_gravatar(this)|trim }}
-          <p class="padding-small">
+          <div role="img" aria-label="Author Gravatar">
+            {{ render_author_gravatar(this)|trim }}
+          </div>
+          <p class="padding-small" aria-live="polite">
             {{ render_authors_byline(this)|trim }}
           </p>
         </div>
@@ -26,7 +28,7 @@ <h2 class="title">{{ this.title }}</h2>
         {% endif %}
       </div>
     </header>
-    <div class="single-post-body content container">
+    <div class="single-post-body content container" aria-labelledby="post-title">
       {{ this.body }}
     </div>
     <footer class="single-post-footer container">
@@ -45,8 +47,8 @@ <h4 class="category-title">Categories</h4>
         </div>
       </div>
       {% if this.series|length %}
-        <div class="series-posts" id="series">
-          <h5 class="title">Posts in the {{ series.name }} series</h5>
+        <div class="series-posts" id="series" aria-labelledby="series-posts-title">
+          <h5 class="title" id="series-posts-title">Posts in the {{ series.name }} series</h5>
           <ul class="posts">
             {% for post in series.children.order_by('pub_date') %}
               {% if post.path==this.path %}
diff --git a/themes/vocabulary_theme/templates/blog-series-list.html b/themes/vocabulary_theme/templates/blog-series-list.html
index 3a323b3b6..41bd678e9 100644
--- a/themes/vocabulary_theme/templates/blog-series-list.html
+++ b/themes/vocabulary_theme/templates/blog-series-list.html
@@ -5,9 +5,9 @@
 {% block title %}All Series{% endblock %}
 
 {% block body %}
-<div class="all-series">
+<div class="all-series" role="region" aria-labelledby="series-title">
   <div class="header">
-    <h1 class="container">All Series</h1>
+    <h1 id="series-title" class="container">All Series</h1>
   </div>
   <div class="series-list container">
     {{ render_series(this) }}
diff --git a/themes/vocabulary_theme/templates/blog.html b/themes/vocabulary_theme/templates/blog.html
index c216824ee..5f078dd4e 100644
--- a/themes/vocabulary_theme/templates/blog.html
+++ b/themes/vocabulary_theme/templates/blog.html
@@ -10,12 +10,15 @@
     <div class="header">
       <div class="container">
         <h1>{{ this.title }}</h1>
-        <div class="description column is-9 is-paddingless">{{ this.description }}</div>
+        <div class="description column is-9 is-paddingless" aria-describedby="blog-description">{{ this.description }}</div>
       </div>
     </div>
     <div class="container blog-page-posts">
-      {{ render_posts(this.pagination.items) }}
-      <div class="pagination-wrapper">
+      <section>
+        <h2 id="blog-posts" class="sr-only">Blog Posts</h2>
+        {{ render_posts(this.pagination.items) }}
+      </section>
+      <div class="pagination-wrapper" aria-live="polite">
         {% if this.pagination.pages > 1 %}
           {{ render_pagination(this.pagination) }}
         {% endif %}
diff --git a/themes/vocabulary_theme/templates/cc-search-guide.html b/themes/vocabulary_theme/templates/cc-search-guide.html
index 1e47da590..0342f665d 100644
--- a/themes/vocabulary_theme/templates/cc-search-guide.html
+++ b/themes/vocabulary_theme/templates/cc-search-guide.html
@@ -12,7 +12,7 @@ <h1>{{ this.title }}</h1>
   <div class="container body">
     <div class="columns">
       <div class="column is-one-quarter">
-        <div class="table-of-progress sticky-top">
+        <nav class="table-of-progress sticky-top" aria-label="Table of contents">
           <h4 class="step-header">Steps</h4>
           <ul>
             {% set step = namespace (number = 0) %}
@@ -21,14 +21,13 @@ <h4 class="step-header">Steps</h4>
                 <li class="step">
                   <a class="link" href="#{{ this.body.toc[loop.index - 2].anchor }}">
                     <span class="number">{{ step.number }}</span>
-                    <span class="name">{{ item.title }}</span>
                   </a>
                 </li>
                 {% set step.number = step.number + 1 %}
-              {% endif%}
+              {% endif %}
             {% endfor %}
           </ul>
-        </div>
+        </nav>
       </div>
       <div class="column content">
         {{ this.body }}
diff --git a/themes/vocabulary_theme/templates/community_team_list.html b/themes/vocabulary_theme/templates/community_team_list.html
index b1d263c7a..c6c5c7108 100644
--- a/themes/vocabulary_theme/templates/community_team_list.html
+++ b/themes/vocabulary_theme/templates/community_team_list.html
@@ -14,10 +14,10 @@ <h1>{{ this.title }}</h1>
       <div class="content">
         <h2>Project Teams</h2>
         {% for project in bag('community_team_members.projects') %}
-          <h3 class="b-header">{{ project.name }}</h3>
-          <p>These team members have permissions in the <code>{{ project.repos }}</code> repo(s).</p>
+        <h3 class="b-header">{{ project.name }}</h3>
+          <p aria-describedby="{{ project.name|lower|replace(' ', '-') }}-repo-info">These team members have permissions in the <code>{{ project.repos }}</code> repo(s).</p>
           <div class="table-container">
-            <table class="table is-bordered is-striped">
+            <table class="table is-bordered is-striped" aria-labelledby="{{ project.name|lower|replace(' ', '-') }}-project">
               <thead>
                 <tr>
                   <th>Role</th>
@@ -27,7 +27,7 @@ <h3 class="b-header">{{ project.name }}</h3>
               {% for member in project.members %}
                 <tr>
                   <td>{{ member.role }}</td>
-                  <td id="{{project.name|lower|replace(' ','-')}}--{{member.name|lower|replace(' ','-')}}">{{ member.name }}</td>
+                  <td id="{{ project.name|lower|replace(' ','-') }}--{{ member.name|lower|replace(' ','-') }}" aria-labelledby="{{ project.name|lower|replace(' ','-') }}--{{ member.name|lower|replace(' ','-') }}">{{ member.name }}</td>
                 </tr>
               {% endfor %}
             </table>
@@ -45,7 +45,7 @@ <h2>Community Building Teams</h2>
             {% for member in bag('community_team_members.community_builders') %}
               <tr>
                 <td>{{ member.role }}</td>
-                <td id="community-builder--{{member.name|replace(' ','-')}}">{{ member.name }}</td>
+                <td id="community-builder--{{ member.name|replace(' ','-') }}" aria-labelledby="community-builder--{{ member.name|replace(' ','-') }}">{{ member.name }}</td>
               </tr>
             {% endfor %}
           </table>
diff --git a/themes/vocabulary_theme/templates/issue_finder.html b/themes/vocabulary_theme/templates/issue_finder.html
index fdf625d2b..604eeeb1e 100644
--- a/themes/vocabulary_theme/templates/issue_finder.html
+++ b/themes/vocabulary_theme/templates/issue_finder.html
@@ -3,7 +3,7 @@
 {% block title %}{{ this.title }}{% endblock %}
 
 {% block body %}
-  <div class="issue-finder">
+  <div class="issue-finder" aria-labelledby="issue-finder-title">
     <div class="header">
       <div class="container is-paddingless">
         <h1>{{ this.title }}</h1>
diff --git a/themes/vocabulary_theme/templates/layout.html b/themes/vocabulary_theme/templates/layout.html
index e750077f6..49b6a2b79 100644
--- a/themes/vocabulary_theme/templates/layout.html
+++ b/themes/vocabulary_theme/templates/layout.html
@@ -1,51 +1,51 @@
 <!doctype html>
 <html lang="en">
-<meta charset="utf-8">
-<meta name="viewport" content="width=device-width, initial-scale=1" />
-<link rel="shortcut icon" type="image/x-icon" href="{{ '/static/favicon.ico'|url }}">
-<link rel="stylesheet" href="{{ '/static/gen/style.css'|url }}">
-<link rel="stylesheet" href="{{ get_pygments_stylesheet()|url }}">
-<meta property="og:site_name" content="Creative Commons" />
-<meta property="og:title" content="{{ this.title }}" />
-{% if this.description %}
-{% set desc = this.description|excerpt|striphtmltags %}
-<meta property="og:description" content="{{ desc }}" />
-{% else %}
-{% if this.body %}
-{% set desc = this.body|excerpt|striphtmltags %}
-<meta property="og:description" content="{{ desc }}" />
-{% endif %}
-{% endif %}
-<meta property="og:url" content="{{ this|url }}" />
-<meta property="og:type" content="article" />
-{% from "macros/og_image.html" import og_image %}
-{{ og_image(this) }}
-<meta name="twitter:card" content="summary_large_image" />
-<meta name="twitter:title" content="{{ this.title }}">
-<meta name="twitter:description" content="{{ desc }}">
-{% if image %}
-<meta name="twitter:image" content="{{ image|url(external=true) }}">
-{% endif %}
-<meta name="twitter:site" content="@creativecommons">
-<meta name="twitter:creator" content="@creativecommons">
-<script src="https://code.jquery.com/jquery-3.3.1.min.js"
-  integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8=" crossorigin="anonymous"></script>
-<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.6/umd/popper.min.js"
-  integrity="sha384-wHAiFfRlMFy6i5SRaxvfOCifBUQy1xHdJ/yoi7FRNXMRBu5WHdZYu1hA6ZOblgut" crossorigin="anonymous"></script>
-<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/js/bootstrap.min.js"
-  integrity="sha384-B0UglyR+jN6CkvvICOB2joaf5I4l3gm9GU6Hc1og6Ls7i6U/mkkaduKaBhlAXv9k" crossorigin="anonymous"></script>
-<script type="text/javascript" src="{{ '/static/gen/script.js'|url }}"></script>
-<script src="https://unpkg.com/@creativecommons/vocabulary@2020.7.2/js/vocabulary.js"></script>
-<script>
-  const globalHeaderInstance = vocabulary.createGlobalHeader();
-</script>
-<title>{% block title %}Welcome{% endblock %} — Creative Commons Open Source</title>
-
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1" />
+  <link rel="shortcut icon" type="image/x-icon" href="{{ '/static/favicon.ico'|url }}">
+  <link rel="stylesheet" href="{{ '/static/gen/style.css'|url }}">
+  <link rel="stylesheet" href="{{ get_pygments_stylesheet()|url }}">
+  <meta property="og:site_name" content="Creative Commons" />
+  <meta property="og:title" content="{{ this.title }}" />
+  {% if this.description %}
+    {% set desc = this.description|excerpt|striphtmltags %}
+    <meta property="og:description" content="{{ desc }}" />
+  {% else %}
+    {% if this.body %}
+      {% set desc = this.body|excerpt|striphtmltags %}
+      <meta property="og:description" content="{{ desc }}" />
+    {% endif %}
+  {% endif %}
+  <meta property="og:url" content="{{ this|url }}" />
+  <meta property="og:type" content="article" />
+  {% from "macros/og_image.html" import og_image %}
+  {{ og_image(this) }}
+  <meta name="twitter:card" content="summary_large_image" />
+  <meta name="twitter:title" content="{{ this.title }}">
+  <meta name="twitter:description" content="{{ desc }}">
+  {% if image %}
+    <meta name="twitter:image" content="{{ image|url(external=true) }}">
+  {% endif %}
+  <meta name="twitter:site" content="@creativecommons">
+  <meta name="twitter:creator" content="@creativecommons">
+  <script src="https://code.jquery.com/jquery-3.3.1.min.js"
+    integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8=" crossorigin="anonymous"></script>
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.6/umd/popper.min.js"
+    integrity="sha384-wHAiFfRlMFy6i5SRaxvfOCifBUQy1xHdJ/yoi7FRNXMRBu5WHdZYu1hA6ZOblgut" crossorigin="anonymous"></script>
+  <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/js/bootstrap.min.js"
+    integrity="sha384-B0UglyR+jN6CkvvICOB2joaf5I4l3gm9GU6Hc1og6Ls7i6U/mkkaduKaBhlAXv9k" crossorigin="anonymous"></script>
+  <script type="text/javascript" src="{{ '/static/gen/script.js'|url }}"></script>
+  <script src="https://unpkg.com/@creativecommons/vocabulary@2020.7.2/js/vocabulary.js"></script>
+  <script>
+    const globalHeaderInstance = vocabulary.createGlobalHeader();
+  </script>
+  <title>{% block title %}Welcome{% endblock %} — Creative Commons Open Source</title>
+</head>
 <body>
-
   <!-- Header -->
   <header class="container">
-    <nav class="navbar">
+    <nav class="navbar" aria-label="Main Navigation">
       <div class="navbar-brand">
         <a class="has-text-black" href="{{ '/'|url }}" aria-label="Home">
           <svg
@@ -62,15 +62,15 @@
           <span aria-hidden="true"></span>
         </a>
       </div>
-      <div class="navbar-menu">
+      <div class="navbar-menu" id="navbar-menu">
         <div class="navbar-end">
           <a class="navbar-item {% if this.is_child_of('/blog') %} is-active{% endif%}" href="{{ '/blog/entries'|url }}">
             Blog
           </a>
-          <div class="navbar-item has-dropdown is-hoverable">
-            <a class="navbar-link is-arrowless {% if this.is_child_of('/contributing-code') %} is-active{% endif%}" tabindex="0">
+          <div class="navbar-item has-dropdown is-hoverable" aria-labelledby="contribute-dropdown">
+            <a class="navbar-link is-arrowless {% if this.is_child_of('/contributing-code') %} is-active{% endif%}" tabindex="0" id="contribute-dropdown">
               Contribute<i class="icon caret-down"></i></a>
-            <div class="navbar-dropdown">
+            <div class="navbar-dropdown" aria-labelledby="contribute-dropdown">
               {% for href, title in [
                 ['/contributing-code', 'Contribution Guidelines'],
                 ['/contributing-code/projects', 'Project List'],
@@ -89,10 +89,10 @@
               {% endfor %}
             </div>
           </div>
-          <div class="navbar-item has-dropdown is-hoverable">
-            <a class="navbar-link is-arrowless {% if this.is_child_of('/community') %} is-active{% endif%}" tabindex="0">
+          <div class="navbar-item has-dropdown is-hoverable" aria-labelledby="community-dropdown">
+            <a class="navbar-link is-arrowless {% if this.is_child_of('/community') %} is-active{% endif%}" tabindex="0" id="community-dropdown">
               Community<i class="icon caret-down"></i></a>
-            <div class="navbar-dropdown is-active">
+            <div class="navbar-dropdown is-active" aria-labelledby="community-dropdown">
               {% for href, title in [
                 ['/community', 'Join the Community'],
                 ['/community/community-team', 'Community Team'],
@@ -108,10 +108,10 @@
               {% endfor %}
             </div>
           </div>
-          <div class="navbar-item has-dropdown is-hoverable">
-            <a class="navbar-link is-arrowless {% if this.is_child_of('/programs') %} is-active{% endif%}" tabindex="0">
+          <div class="navbar-item has-dropdown is-hoverable" aria-labelledby="work-programs-dropdown">
+            <a class="navbar-link is-arrowless {% if this.is_child_of('/programs') %} is-active{% endif%}" tabindex="0" id="work-programs-dropdown">
               Work Programs<i class="icon caret-down"></i></a>
-            <div class="navbar-dropdown">
+            <div class="navbar-dropdown" aria-labelledby="work-programs-dropdown">
               {% for href, title in [
                 ['/programs', 'Overview'],
                 ['/programs/project-ideas', 'Project Ideas'],
@@ -146,7 +146,7 @@
           {% for crumb in crumbs %}
             <!-- Active link -->
             {% if this._slug == crumb %}
-              <li class="is-active"><a aria-current="page displayed">{{ this.title }}</a></li>
+              <li class="is-active"><a aria-current="page">{{ this.title }}</a></li>
             {% else %}
               <!-- Forming the URL using extracted slugs -->
               {% set i = loop.index %}
diff --git a/themes/vocabulary_theme/templates/macros/authors_gravatar.html b/themes/vocabulary_theme/templates/macros/authors_gravatar.html
index 2c7cce45e..3bebf7141 100644
--- a/themes/vocabulary_theme/templates/macros/authors_gravatar.html
+++ b/themes/vocabulary_theme/templates/macros/authors_gravatar.html
@@ -1,15 +1,15 @@
 {% macro render_author_gravatar(post, skip_gravatar=false) %}
   {% if not skip_gravatar %}
-    {# only display gravatar for first author so layout is broken #}
+    {# only display gravatar for first author so layout is not broken #}
     {% set author = post.author[0] %}
     {% set current_author = post.parent.parent.children.get('authors').children.get(author) %}
     <header>
       <figure class="image blog-image">
-    {% if post.author|length >= 2 %}
-        <img class="profile" src="/multiple-authors.jpg" alt="multiple authors image"/>
-    {% else %}
-        <img class="profile" src="https://secure.gravatar.com/avatar/{{ current_author.md5_hashed_email }}?size=200&d=mp" alt="author's gravatar" />
-    {% endif %}
+        {% if post.author|length >= 2 %}
+          <img class="profile" src="/multiple-authors.jpg" alt="multiple authors image" />
+        {% else %}
+          <img class="profile" src="https://secure.gravatar.com/avatar/{{ current_author.md5_hashed_email }}?size=200&d=mp" alt="author's gravatar" />
+        {% endif %}
       </figure>
     </header>
   {% endif %}
diff --git a/themes/vocabulary_theme/templates/macros/og_image.html b/themes/vocabulary_theme/templates/macros/og_image.html
index 6f363d795..41d02b202 100644
--- a/themes/vocabulary_theme/templates/macros/og_image.html
+++ b/themes/vocabulary_theme/templates/macros/og_image.html
@@ -15,11 +15,12 @@
     {% if author and author.md5_hashed_email %}
       {% set gravatarURL = 'https://secure.gravatar.com/avatar/' + author.md5_hashed_email + '?size=300&d=mp' %}
       {% set queryParams = queryParams + '&images=' + gravatarURL %}
-      {% set pageTitle = page.title + "<br><sm style='font-size:70px;'>By " + render_author_name(author) + "</sm>"  %}
+      {% set pageTitle = page.title + "<br><sm style='font-size:70px;'>By " + render_author_name(author) + "</sm>" %}
     {% endif  %}
   {% endif %}
 
   {% set url = baseUrl + pageTitle + '.png' + queryParams  %}
 
   <meta property="og:image" content="{{ url }}" />
+  <meta name="description" content="{{ pageTitle }} - CC Open Source" />
 {% endmacro %}
diff --git a/themes/vocabulary_theme/templates/macros/series.html b/themes/vocabulary_theme/templates/macros/series.html
index 87b77b8b1..af918c5df 100644
--- a/themes/vocabulary_theme/templates/macros/series.html
+++ b/themes/vocabulary_theme/templates/macros/series.html
@@ -1,7 +1,13 @@
 {% from "macros/posts.html" import render_posts %}
 
 {% macro render_series(series) %}
-  {% for serie in site.query(series.path) %}
-    <h4 class="series-link"><a class="link" href="{{ serie|url }}">{{ serie.name }}</a></h4>
-  {% endfor %}
+  <div role="region" aria-labelledby="series-list">
+    <h2 id="series-list" class="visually-hidden">List of Series</h2>
+    {% for serie in site.query(series.path) %}
+      <h4 class="series-link">
+        <a class="link" href="{{ serie|url }}" aria-label="View series: {{ serie.name }}">{{ serie.name }}</a>
+      </h4>
+    {% endfor %}
+  </div>
 {% endmacro %}
+
diff --git a/themes/vocabulary_theme/templates/page-with-title.html b/themes/vocabulary_theme/templates/page-with-title.html
index 6e18d7084..5bfcac85c 100644
--- a/themes/vocabulary_theme/templates/page-with-title.html
+++ b/themes/vocabulary_theme/templates/page-with-title.html
@@ -3,10 +3,10 @@
 {% block title %}{{ this.title }}{% endblock %}
 
 {% block body %}
-  <div class="code-guidelines">
+  <div class="code-guidelines" role="region" aria-labelledby="page-title">
     <header class="header">
       <div class="container is-paddingless">
-        <h1>{{ this.title }}</h1>
+        <h1 id="page-title">{{ this.title }}</h1>
         <div class="description column is-9 is-paddingless">
           {{ this.description }}
         </div>
diff --git a/themes/vocabulary_theme/templates/project-ideas.html b/themes/vocabulary_theme/templates/project-ideas.html
index 6eb0be72c..8e21bd06e 100644
--- a/themes/vocabulary_theme/templates/project-ideas.html
+++ b/themes/vocabulary_theme/templates/project-ideas.html
@@ -9,7 +9,7 @@
         <h1>Open Source Work Programs: Project Ideas</h1>
         <p class="description">This is the project idea list for the <span class="has-color-forest-green">current round of open source collaborations at Creative Commons (CC).</span></p>
         {% set ideas = site.query('/programs/project-ideas-collection').include_undiscoverable(true) %}
-        <div class="filter-labels" id="project-list">
+        <div class="filter-labels" id="project-list" aria-label="Project Filters">
           <button type="button" class="button tag btn-dark filter-btn" data-filter="all">
             All Projects
           </button>
@@ -63,7 +63,7 @@ <h5 class="card-title">{{ idea.title }}</h5>
             </a>
           </div>
           {% endfor %}
-          <div class="column is-one-quarter">
+          <div class="column is-one-quarter" role="listitem">
             <a href="#original-ideas">
               <article class="card entry-post horizontal">
                 <div class="card-content">
@@ -77,8 +77,8 @@ <h5 class="card-title">Original Ideas</h5>
     </div>
     <div class="body container">
       {% for idea in ideas %}
-        <div class="project-idea">
-          <h2><a class="has-color-dark-slate-gray" name="{{ idea._slug }}">{{ idea.title }}</a></h2>
+        <div class="project-idea" role="region" aria-labelledby="{{ idea._slug }}">
+          <h2><a class="has-color-dark-slate-gray" name="{{ idea._slug }}" id="{{ idea._slug }}">{{ idea.title }}</a></h2>
           <div class="columns">
             <div class="column is-one-quarter">
               <h5 class="b-header padding-bottom-small">Difficulty</h5>