diff --git a/board/forms.py b/board/forms.py
index 12cdedb..df239e5 100644
--- a/board/forms.py
+++ b/board/forms.py
@@ -6,6 +6,7 @@ from django import forms
 from django.forms import ModelForm, ModelChoiceField
 from django.forms.models import fields_for_model
 from django.utils import timezone
+from django.utils.translation import gettext as _
 from guardian.shortcuts import get_objects_for_user
 from board.models import Ban, Post, Report, ReportReason, ReportRecord
 from hcaptcha.fields import hCaptchaField
@@ -38,7 +39,7 @@ class PostForm(ModelForm):
         capcode = self.cleaned_data["capcode"]
         if capcode:
             if not self.user or not self.user.has_perm("board.use_capcode", capcode):
-                raise ValidationError("Could not create post")
+                raise ValidationError(_("Could not create post"))
 
 
 class ReplyForm(PostForm):
@@ -67,10 +68,12 @@ class ReplyForm(PostForm):
 
     def clean(self):
         super().clean()
+        if self.instance.op.lock:
+            raise ValidationError(_("This thread is locked, you cannot reply to it"))
         capcode = self.cleaned_data["capcode"]
         if capcode:
             if not self.user or not self.user.has_perm("board.use_capcode", capcode):
-                raise ValidationError("Could not create post")
+                raise ValidationError(_("Could not create post"))
 
 
 class ReportForm(ModelForm):
@@ -142,7 +145,7 @@ class PostModifyForm(ModelForm):
         model = Post
         # we specify fields up here too because otherwise they won't be
         # recognized by the form to update values
-        fields = ["sticky", "bump"]
+        fields = ["sticky", "bump", "lock"]
 
     def __init__(self, *args, user, **kwargs):
         super(PostModifyForm, self).__init__(*args, **kwargs)
@@ -152,6 +155,8 @@ class PostModifyForm(ModelForm):
             fields += ["sticky"]
         if self.user.has_perm("board.set_bump"):
             fields += ["bump"]
+        if self.user.has_perm("board.set_lock") and not self.instance.op:
+            fields += ["lock"]
         # NOTE:
         # We do *not* need to check permissions against these fields we're
         # setting down here in the self.clean() function in the case that a
diff --git a/board/models.py b/board/models.py
index 74f00ba..12c4c30 100644
--- a/board/models.py
+++ b/board/models.py
@@ -93,8 +93,10 @@ class Post(models.Model):
     ip = models.GenericIPAddressField()
     # Capcode
     capcode = models.ForeignKey("Capcode", null=True, blank=True, on_delete=SET_NULL)
-    # Post is stickied
+    # Post is stickied - it remains at the top of the bump list.
     sticky = models.BooleanField(default=False, blank=True)
+    # Post is locked - nobody can post in it.
+    lock = models.BooleanField(default=False, blank=True)
     # Creation time
     created = models.DateTimeField(auto_now_add=True)
     # Last bump time
@@ -122,6 +124,7 @@ class Post(models.Model):
         permissions = [
             ("set_sticky", "Can sticky post"),
             ("set_bump", "Can bumplock post"),
+            ("set_lock", "Can lock post"),
         ]
 
     def save(self, *args, **kwargs):
diff --git a/board/templates/board/post_snippet.html b/board/templates/board/post_snippet.html
index 2583eca..85ad8c1 100644
--- a/board/templates/board/post_snippet.html
+++ b/board/templates/board/post_snippet.html
@@ -27,9 +27,12 @@
 </div>
 {% endif %}
 
-{# Post ID, sticky, username, time #}
+{# Post ID, status icons, username, time #}
 {% if post.sticky and not post.op %}
-<span title="Stickied" class="fa fa-sticky-note"></span>
+<span title="Stickied" class="fa fa-thumb-tack"></span>
+{% endif %}
+{% if post.lock and not post.op %}
+<span title="Locked" class="fa fa-lock"></span>
 {% endif %}
 <a href="#p{{post.id}}">#.</a>
 <span class="post_id">{{post.id}}</span>
diff --git a/board/templates/board/reply_create_view.html b/board/templates/board/reply_create_view.html
index bef694a..8bebc2a 100644
--- a/board/templates/board/reply_create_view.html
+++ b/board/templates/board/reply_create_view.html
@@ -28,17 +28,32 @@ input[type=text] {
 {% block content %}
 <form method="post" action="{% url 'board:reply_create' url=board.url id=post.id %}" enctype="multipart/form-data">
     {% csrf_token %}
+    {% if form.errors %}
+        {{form.non_field_errors}}
+    {% endif %}
     <table>
     {% for field in form %}
         {% if field.name != "capcode" %}
-        <tr>
-            <th>{{field.label_tag}}</th>
-            <td>{{field}}</td>
-        </tr>
+            {% if field.errors %}
+            <tr>
+                <th></th>
+                <td>{{field.errors}}</td>
+            </tr>
+            {% endif %}
+            <tr>
+                <th>{{field.label_tag}}</th>
+                <td>{{field}}</td>
+            </tr>
         {% endif %}
     {% endfor %}
     {% if capcodes %}
     <tr>
+        {% if form.capcode.errors %}
+        <tr>
+            <th></th>
+            <td>{{form.capcode.errors}}</td>
+        </tr>
+        {% endif %}
         <th>{{form.capcode.label_tag}}</th>
         <td>
             {{form.capcode}}