diff --git a/app/assets/javascripts/discourse/app/components/flag-action-type.js b/app/assets/javascripts/discourse/app/components/flag-action-type.js
index 0041814118b..963742bf18e 100644
--- a/app/assets/javascripts/discourse/app/components/flag-action-type.js
+++ b/app/assets/javascripts/discourse/app/components/flag-action-type.js
@@ -14,7 +14,9 @@ export default Component.extend({
 
   @discourseComputed("flag.name_key")
   customPlaceholder(nameKey) {
-    return I18n.t("flagging.custom_placeholder_" + nameKey);
+    return I18n.t("flagging.custom_placeholder_" + nameKey, {
+      defaultValue: I18n.t("flagging.custom_placeholder_notify_moderators"),
+    });
   },
 
   @discourseComputed("flag.name", "flag.name_key", "username")
@@ -22,7 +24,9 @@ export default Component.extend({
     if (["notify_user", "notify_moderators"].includes(nameKey)) {
       return name.replace(/{{username}}|%{username}/, username);
     } else {
-      return I18n.t("flagging.formatted_name." + nameKey);
+      return I18n.t("flagging.formatted_name." + nameKey, {
+        defaultValue: name,
+      });
     }
   },
 
diff --git a/app/assets/javascripts/discourse/app/lib/transform-post.js b/app/assets/javascripts/discourse/app/lib/transform-post.js
index 35db31b6feb..8c96353a63e 100644
--- a/app/assets/javascripts/discourse/app/lib/transform-post.js
+++ b/app/assets/javascripts/discourse/app/lib/transform-post.js
@@ -254,7 +254,11 @@ export default function transformPost(
           postId: post.id,
           action,
           canUndo: a.can_undo,
-          description: I18n.t(`post.actions.by_you.${action}`),
+          description: I18n.t(`post.actions.by_you.${action}`, {
+            defaultValue: I18n.t(`post.actions.by_you.custom`, {
+              custom: a.actionType.name,
+            }),
+          }),
         };
       });
   }
diff --git a/app/models/flag.rb b/app/models/flag.rb
new file mode 100644
index 00000000000..5085d0246a2
--- /dev/null
+++ b/app/models/flag.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+class Flag < ActiveRecord::Base
+  MAX_SYSTEM_FLAG_ID = 1000
+  scope :enabled, -> { where(enabled: true) }
+  scope :system, -> { where("id < 1000") }
+
+  before_save :set_position
+  before_save :set_name_key
+  after_save :reset_flag_settings!
+  after_destroy :reset_flag_settings!
+
+  default_scope { order(:position) }
+
+  def used?
+    PostAction.exists?(post_action_type_id: self.id) ||
+      ReviewableScore.exists?(reviewable_score_type: self.id)
+  end
+
+  def self.reset_flag_settings!
+    # Flags are memoized for better performance. After the update, we need to reload them in all processes.
+    PostActionType.reload_types
+    DiscourseEvent.trigger(:reload_post_action_types)
+  end
+
+  def system?
+    self.id < MAX_SYSTEM_FLAG_ID
+  end
+
+  def applies_to?(type)
+    self.applies_to.include?(type)
+  end
+
+  private
+
+  def reset_flag_settings!
+    self.class.reset_flag_settings!
+  end
+
+  def set_position
+    self.position = Flag.maximum(:position).to_i + 1 if !self.position
+  end
+
+  def set_name_key
+    self.name_key = self.name.squeeze(" ").gsub(" ", "_").gsub(/[^\w]/, "").downcase
+  end
+end
+
+# == Schema Information
+#
+# Table name: flags
+#
+#  id               :bigint           not null, primary key
+#  name             :string
+#  name_key         :string
+#  description      :text
+#  notify_type      :boolean          default(FALSE), not null
+#  auto_action_type :boolean          default(FALSE), not null
+#  custom_type      :boolean          default(FALSE), not null
+#  applies_to       :string           not null, is an Array
+#  position         :integer          not null
+#  enabled          :boolean          default(TRUE), not null
+#  created_at       :datetime         not null
+#  updated_at       :datetime         not null
+#
diff --git a/app/models/post_action_type.rb b/app/models/post_action_type.rb
index 9b49575e3b7..0c596d9055e 100644
--- a/app/models/post_action_type.rb
+++ b/app/models/post_action_type.rb
@@ -11,39 +11,47 @@ class PostActionType < ActiveRecord::Base
     ApplicationSerializer.expire_cache_fragment!(/\Apost_action_flag_types_/)
   end
 
+  DiscourseEvent.on(:reload_post_action_types) { self.reload_types }
+
   class << self
     attr_reader :flag_settings
 
-    def replace_flag_settings(settings)
-      if settings
-        @flag_settings = settings
-      else
-        initialize_flag_settings
-      end
-      @types = nil
+    def initialize_flag_settings
+      @flag_settings = FlagSettings.new
     end
 
-    def ordered
-      order("position asc")
+    def replace_flag_settings(settings)
+      Discourse.deprecate("Flags should not be replaced. Insert custom flags as database records.")
+      @flag_settings = settings || FlagSettings.new
+      @all_flags = nil
     end
 
     def types
-      unless @types
-        # NOTE: Previously bookmark was type 1 but that has been superseded
-        # by the separate Bookmark model and functionality
-        @types = Enum.new(like: 2)
-        @types.merge!(flag_settings.flag_types)
-      end
+      return Enum.new(like: 2).merge!(flag_settings.flag_types) if overridden_by_plugin?
+      Enum.new(like: 2).merge(flag_types)
+    end
 
-      @types
+    def reload_types
+      @all_flags = nil
+      @flag_settings = FlagSettings.new
+      ReviewableScore.reload_types
+    end
+
+    def overridden_by_plugin?
+      flag_settings.flag_types.present?
+    end
+
+    def all_flags
+      @all_flags ||= Flag.all
     end
 
     def auto_action_flag_types
-      flag_settings.auto_action_types
+      return flag_settings.auto_action_types if overridden_by_plugin?
+      flag_enum(all_flags.select(&:auto_action_type))
     end
 
     def public_types
-      @public_types ||= types.except(*flag_types.keys << :notify_user)
+      types.except(*flag_types.keys << :notify_user)
     end
 
     def public_type_ids
@@ -51,11 +59,13 @@ class PostActionType < ActiveRecord::Base
     end
 
     def flag_types_without_custom
-      flag_settings.without_custom_types
+      return flag_settings.without_custom_types if overridden_by_plugin?
+      flag_enum(all_flags.reject(&:custom_type))
     end
 
     def flag_types
-      flag_settings.flag_types
+      return flag_settings.flag_types if overridden_by_plugin?
+      flag_enum(all_flags)
     end
 
     # flags resulting in mod notifications
@@ -64,15 +74,25 @@ class PostActionType < ActiveRecord::Base
     end
 
     def notify_flag_types
-      flag_settings.notify_types
+      return flag_settings.notify_types if overridden_by_plugin?
+      flag_enum(all_flags.select(&:notify_type))
     end
 
     def topic_flag_types
-      flag_settings.topic_flag_types
+      if overridden_by_plugin?
+        flag_settings.topic_flag_types
+      else
+        flag_enum(all_flags.select { |flag| flag.applies_to?("Topic") })
+      end
     end
 
     def custom_types
-      flag_settings.custom_types
+      return flag_settings.custom_types if overridden_by_plugin?
+      flag_enum(all_flags.select(&:custom_type))
+    end
+
+    def names
+      all_flags.pluck(:id, :name).to_h
     end
 
     def is_flag?(sym)
@@ -81,28 +101,8 @@ class PostActionType < ActiveRecord::Base
 
     private
 
-    def initialize_flag_settings
-      @flag_settings = FlagSettings.new
-      @flag_settings.add(3, :off_topic, notify_type: true, auto_action_type: true)
-      @flag_settings.add(
-        4,
-        :inappropriate,
-        topic_type: true,
-        notify_type: true,
-        auto_action_type: true,
-      )
-      @flag_settings.add(8, :spam, topic_type: true, notify_type: true, auto_action_type: true)
-      @flag_settings.add(6, :notify_user, topic_type: false, notify_type: false, custom_type: true)
-      @flag_settings.add(
-        7,
-        :notify_moderators,
-        topic_type: true,
-        notify_type: true,
-        custom_type: true,
-      )
-      @flag_settings.add(10, :illegal, topic_type: true, notify_type: true, custom_type: true)
-      # When adding a new ID here, check that it doesn't clash with any added in
-      # `ReviewableScore.types`. You can thank me later.
+    def flag_enum(scope)
+      Enum.new(scope.map { |flag| [flag.name_key.to_sym, flag.id] }.to_h)
     end
   end
 
diff --git a/app/serializers/post_action_type_serializer.rb b/app/serializers/post_action_type_serializer.rb
index c898b582a11..7f42c654e9a 100644
--- a/app/serializers/post_action_type_serializer.rb
+++ b/app/serializers/post_action_type_serializer.rb
@@ -14,25 +14,25 @@ class PostActionTypeSerializer < ApplicationSerializer
   end
 
   def name
-    i18n("title")
+    i18n("title", default: object.class.names[object.id])
   end
 
   def description
-    i18n("description", tos_url: tos_url, base_path: Discourse.base_path)
+    i18n("description", vars: { tos_url:, base_path: Discourse.base_path })
   end
 
   def short_description
-    i18n("short_description", tos_url: tos_url, base_path: Discourse.base_path)
+    i18n("short_description", vars: { tos_url: tos_url, base_path: Discourse.base_path })
   end
 
   def name_key
-    PostActionType.types[object.id]
+    PostActionType.types[object.id].to_s
   end
 
   protected
 
-  def i18n(field, vars = nil)
+  def i18n(field, default: nil, vars: nil)
     key = "post_action_types.#{name_key}.#{field}"
-    vars ? I18n.t(key, vars) : I18n.t(key)
+    vars ? I18n.t(key, vars, default: default) : I18n.t(key, default: default)
   end
 end
diff --git a/app/serializers/reviewable_score_type_serializer.rb b/app/serializers/reviewable_score_type_serializer.rb
index 5db84b89201..5737134f9ab 100644
--- a/app/serializers/reviewable_score_type_serializer.rb
+++ b/app/serializers/reviewable_score_type_serializer.rb
@@ -9,8 +9,9 @@ class ReviewableScoreTypeSerializer < ApplicationSerializer
 
   # Allow us to share post action type translations for backwards compatibility
   def title
-    I18n.t("post_action_types.#{ReviewableScore.types[id]}.title", default: nil) ||
-      I18n.t("reviewable_score_types.#{ReviewableScore.types[id]}.title")
+    I18n.t("post_action_types.#{type}.title", default: nil) ||
+      I18n.t("reviewable_score_types.#{type}.title", default: nil) ||
+      PostActionType.flag_settings.names[id]
   end
 
   def reviewable_priority
diff --git a/app/serializers/site_serializer.rb b/app/serializers/site_serializer.rb
index 1f5bed13b85..d420a116e65 100644
--- a/app/serializers/site_serializer.rb
+++ b/app/serializers/site_serializer.rb
@@ -350,13 +350,6 @@ class SiteSerializer < ApplicationSerializer
   private
 
   def ordered_flags(flags)
-    notify_moderators_type = PostActionType.flag_types[:notify_moderators]
-    types = flags
-
-    if notify_moderators_flag = types.index(notify_moderators_type)
-      types.insert(types.length, types.delete_at(notify_moderators_flag))
-    end
-
-    types.map { |id| PostActionType.new(id: id) }
+    flags.map { |id| PostActionType.new(id: id) }
   end
 end
diff --git a/app/serializers/topic_flag_type_serializer.rb b/app/serializers/topic_flag_type_serializer.rb
index ccee54a0aaf..a53a09356ff 100644
--- a/app/serializers/topic_flag_type_serializer.rb
+++ b/app/serializers/topic_flag_type_serializer.rb
@@ -3,8 +3,8 @@
 class TopicFlagTypeSerializer < PostActionTypeSerializer
   protected
 
-  def i18n(field, vars = nil)
+  def i18n(field, default: nil, vars: nil)
     key = "topic_flag_types.#{name_key}.#{field}"
-    vars ? I18n.t(key, vars) : I18n.t(key)
+    vars ? I18n.t(key, vars, default: default) : I18n.t(key, default: default)
   end
 end
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index 2711e449c50..db4461ba88c 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -3771,6 +3771,7 @@ en:
           illegal: "You flagged this as illegal"
           notify_moderators: "You flagged this for moderation"
           notify_user: "You sent a message to this user"
+          custom: "You flagged this topic as %{custom}"
 
       delete:
         confirm:
diff --git a/db/fixtures/003_flags.rb b/db/fixtures/003_flags.rb
new file mode 100644
index 00000000000..2e5aa43d1a3
--- /dev/null
+++ b/db/fixtures/003_flags.rb
@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+Flag.seed do |s|
+  s.id = 3
+  s.name = "off_topic"
+  s.position = 2
+  s.notify_type = true
+  s.auto_action_type = true
+  s.custom_type = false
+  s.applies_to = %w[Post Chat::Message]
+end
+Flag.seed do |s|
+  s.id = 4
+  s.name = "inappropriate"
+  s.position = 3
+  s.notify_type = true
+  s.auto_action_type = true
+  s.custom_type = false
+  s.applies_to = %w[Post Topic Chat::Message]
+end
+Flag.seed do |s|
+  s.id = 8
+  s.name = "spam"
+  s.position = 4
+  s.notify_type = true
+  s.auto_action_type = true
+  s.custom_type = false
+  s.applies_to = %w[Post Topic Chat::Message]
+end
+Flag.seed do |s|
+  s.id = 6
+  s.name = "notify_user"
+  s.position = 0
+  s.notify_type = false
+  s.auto_action_type = false
+  s.custom_type = true
+  s.applies_to = %w[Post Chat::Message]
+end
+Flag.seed do |s|
+  s.id = 7
+  s.name = "notify_moderators"
+  s.position = 1
+  s.notify_type = true
+  s.auto_action_type = false
+  s.custom_type = true
+  s.applies_to = %w[Post Topic Chat::Message]
+end
+Flag.seed do |s|
+  s.id = 10
+  s.name = "illegal"
+  s.position = 5
+  s.notify_type = true
+  s.auto_action_type = false
+  s.custom_type = true
+  s.applies_to = %w[Post Topic Chat::Message]
+end
diff --git a/db/migrate/20181031165343_add_flag_stats_to_user.rb b/db/migrate/20181031165343_add_flag_stats_to_user.rb
index fa60e609557..6e0d42c00d5 100644
--- a/db/migrate/20181031165343_add_flag_stats_to_user.rb
+++ b/db/migrate/20181031165343_add_flag_stats_to_user.rb
@@ -18,7 +18,7 @@ class AddFlagStatsToUser < ActiveRecord::Migration[5.2]
           SUM(CASE WHEN pa.deferred_at IS NOT NULL THEN 1 ELSE 0 END) as flags_ignored
         FROM post_actions AS pa
         INNER JOIN users AS u ON u.id = pa.user_id
-        WHERE pa.post_action_type_id IN (#{PostActionType.notify_flag_types.values.join(", ")})
+        WHERE pa.post_action_type_id IN (3, 4, 8, 7, 10)
         AND pa.user_id > 0
         GROUP BY u.id
       ) AS x
diff --git a/db/migrate/20240423054323_create_flags.rb b/db/migrate/20240423054323_create_flags.rb
new file mode 100644
index 00000000000..655785336e6
--- /dev/null
+++ b/db/migrate/20240423054323_create_flags.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+class CreateFlags < ActiveRecord::Migration[7.0]
+  def change
+    create_table :flags do |t|
+      t.string :name, unique: true
+      t.string :name_key, unique: true
+      t.text :description
+      t.boolean :notify_type, default: false, null: false
+      t.boolean :auto_action_type, default: false, null: false
+      t.boolean :custom_type, default: false, null: false
+      t.string :applies_to, array: true, null: false
+      t.integer :position, null: false
+      t.boolean :enabled, default: true, null: false
+      t.timestamps
+    end
+    # IDs below 1000 are reserved for system flags
+    DB.exec("SELECT setval('flags_id_seq', #{Flag::MAX_SYSTEM_FLAG_ID + 1}, FALSE);")
+  end
+end
diff --git a/lib/flag_settings.rb b/lib/flag_settings.rb
index d88c01e35af..7dbce78331f 100644
--- a/lib/flag_settings.rb
+++ b/lib/flag_settings.rb
@@ -7,6 +7,7 @@ class FlagSettings
     :topic_flag_types,
     :auto_action_types,
     :custom_types,
+    :names,
   )
 
   def initialize
@@ -16,18 +17,28 @@ class FlagSettings
     @auto_action_types = Enum.new
     @custom_types = Enum.new
     @without_custom_types = Enum.new
+    @names = Enum.new
   end
 
-  def add(id, name, topic_type: nil, notify_type: nil, auto_action_type: nil, custom_type: nil)
-    @all_flag_types[name] = id
-    @topic_flag_types[name] = id if !!topic_type
-    @notify_types[name] = id if !!notify_type
-    @auto_action_types[name] = id if !!auto_action_type
+  def add(
+    id,
+    name_key,
+    topic_type: nil,
+    notify_type: nil,
+    auto_action_type: nil,
+    custom_type: nil,
+    name: nil
+  )
+    @all_flag_types[name_key] = id
+    @topic_flag_types[name_key] = id if !!topic_type
+    @notify_types[name_key] = id if !!notify_type
+    @auto_action_types[name_key] = id if !!auto_action_type
+    @names[id] = name if name
 
     if !!custom_type
-      @custom_types[name] = id
+      @custom_types[name_key] = id
     else
-      @without_custom_types[name] = id
+      @without_custom_types[name_key] = id
     end
   end
 
diff --git a/lib/guardian.rb b/lib/guardian.rb
index 63846a7a742..b88c9292d55 100644
--- a/lib/guardian.rb
+++ b/lib/guardian.rb
@@ -4,6 +4,7 @@ require "guardian/bookmark_guardian"
 require "guardian/category_guardian"
 require "guardian/ensure_magic"
 require "guardian/group_guardian"
+require "guardian/flag_guardian"
 require "guardian/post_guardian"
 require "guardian/post_revision_guardian"
 require "guardian/sidebar_guardian"
@@ -16,6 +17,7 @@ class Guardian
   include BookmarkGuardian
   include CategoryGuardian
   include EnsureMagic
+  include FlagGuardian
   include GroupGuardian
   include PostGuardian
   include PostRevisionGuardian
diff --git a/lib/guardian/flag_guardian.rb b/lib/guardian/flag_guardian.rb
new file mode 100644
index 00000000000..302f84b9a74
--- /dev/null
+++ b/lib/guardian/flag_guardian.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module FlagGuardian
+  def can_edit_flag?(flag)
+    @user.admin? && !flag.system? && !flag.used?
+  end
+end
diff --git a/lib/plugin/instance.rb b/lib/plugin/instance.rb
index a29e5b13ab5..290c69d6e56 100644
--- a/lib/plugin/instance.rb
+++ b/lib/plugin/instance.rb
@@ -197,6 +197,9 @@ class Plugin::Instance
 
   # Applies to all sites in a multisite environment. Ignores plugin.enabled?
   def replace_flags(settings: ::FlagSettings.new, score_type_names: [])
+    Discourse.deprecate(
+      "replace flags should not be used as flags were moved to the database. Instead, a flag record should be added to the database. Alternatively, soon, the admin will be able to do this in the admin panel.",
+    )
     next_flag_id = ReviewableScore.types.values.max + 1
 
     yield(settings, next_flag_id) if block_given?
diff --git a/plugins/chat/assets/javascripts/discourse/lib/chat-message-flag.js b/plugins/chat/assets/javascripts/discourse/lib/chat-message-flag.js
index bb2f1b7e591..febcfceddad 100644
--- a/plugins/chat/assets/javascripts/discourse/lib/chat-message-flag.js
+++ b/plugins/chat/assets/javascripts/discourse/lib/chat-message-flag.js
@@ -35,7 +35,10 @@ export default class ChatMessageFlag {
     return flags.map((flag) => {
       flag.set(
         "description",
-        I18n.t(`chat.flags.${flag.name_key}`, { basePath: getURL("") })
+        I18n.t(`chat.flags.${flag.name_key}`, {
+          basePath: getURL(""),
+          defaultValue: "",
+        })
       );
       return flag;
     });
diff --git a/plugins/chat/spec/services/chat/flag_message_spec.rb b/plugins/chat/spec/services/chat/flag_message_spec.rb
index f3e326604ce..499c2183053 100644
--- a/plugins/chat/spec/services/chat/flag_message_spec.rb
+++ b/plugins/chat/spec/services/chat/flag_message_spec.rb
@@ -22,7 +22,7 @@ RSpec.describe Chat::FlagMessage do
     let(:guardian) { Guardian.new(current_user) }
     let(:channel_id) { channel_1.id }
     let(:message_id) { message_1.id }
-    let(:flag_type_id) { ReviewableScore.types.values.first }
+    let(:flag_type_id) { ReviewableScore.types[:off_topic] }
     let(:message) { nil }
     let(:is_warning) { nil }
     let(:take_action) { nil }
diff --git a/plugins/discourse-narrative-bot/spec/discourse_narrative_bot/new_user_narrative_spec.rb b/plugins/discourse-narrative-bot/spec/discourse_narrative_bot/new_user_narrative_spec.rb
index e38c195de2e..6a05d12755e 100644
--- a/plugins/discourse-narrative-bot/spec/discourse_narrative_bot/new_user_narrative_spec.rb
+++ b/plugins/discourse-narrative-bot/spec/discourse_narrative_bot/new_user_narrative_spec.rb
@@ -1032,7 +1032,7 @@ RSpec.describe DiscourseNarrativeBot::NewUserNarrative do
       let(:another_post) { Fabricate(:post, user: discobot_user, topic: topic) }
       let(:flag) do
         Fabricate(
-          :flag,
+          :flag_post_action,
           post: post,
           user: user,
           post_action_type_id: PostActionType.types[:inappropriate],
@@ -1040,7 +1040,7 @@ RSpec.describe DiscourseNarrativeBot::NewUserNarrative do
       end
       let(:other_flag) do
         Fabricate(
-          :flag,
+          :flag_post_action,
           post: another_post,
           user: user,
           post_action_type_id: PostActionType.types[:spam],
@@ -1166,7 +1166,7 @@ RSpec.describe DiscourseNarrativeBot::NewUserNarrative do
 
       describe "when post contain the right answer" do
         let(:post) { Fabricate(:post, user: discobot_user, topic: topic) }
-        let(:flag) { Fabricate(:flag, post: post, user: user) }
+        let(:flag) { Fabricate(:flag_post_action, post: post, user: user) }
 
         before do
           narrative.set_data(user, state: :tutorial_flag, topic_id: topic.id)
diff --git a/spec/fabricators/flag_fabricator.rb b/spec/fabricators/flag_fabricator.rb
index d4b30c52377..792da20f55f 100644
--- a/spec/fabricators/flag_fabricator.rb
+++ b/spec/fabricators/flag_fabricator.rb
@@ -1,7 +1,3 @@
 # frozen_string_literal: true
 
-Fabricator(:flag, from: :post_action) do
-  user
-  post
-  post_action_type_id PostActionType.types[:spam]
-end
+Fabricator(:flag) { name "offtopic", applies_to { %w[Post Chat::Message] } }
diff --git a/spec/fabricators/flag_post_action_fabricator.rb b/spec/fabricators/flag_post_action_fabricator.rb
new file mode 100644
index 00000000000..77f44a6078f
--- /dev/null
+++ b/spec/fabricators/flag_post_action_fabricator.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+Fabricator(:flag_post_action, from: :post_action) do
+  user
+  post
+  post_action_type_id PostActionType.types[:spam]
+end
diff --git a/spec/lib/composer_messages_finder_spec.rb b/spec/lib/composer_messages_finder_spec.rb
index 62b3776fd42..1d9c09d7fb9 100644
--- a/spec/lib/composer_messages_finder_spec.rb
+++ b/spec/lib/composer_messages_finder_spec.rb
@@ -360,7 +360,7 @@ RSpec.describe ComposerMessagesFinder do
     end
 
     it "shows a message when the replier has already flagged the post" do
-      Fabricate(:flag, post: self_flagged_post, user: user)
+      Fabricate(:flag_post_action, post: self_flagged_post, user: user)
       finder =
         ComposerMessagesFinder.new(
           user,
@@ -372,13 +372,13 @@ RSpec.describe ComposerMessagesFinder do
     end
 
     it "shows a message when replying to flagged topic (first post)" do
-      Fabricate(:flag, post: original_post, user: user)
+      Fabricate(:flag_post_action, post: original_post, user: user)
       finder = ComposerMessagesFinder.new(user, composer_action: "reply", topic_id: topic.id)
       expect(finder.check_dont_feed_the_trolls).to be_present
     end
 
     it "does not show a message when not enough others have flagged the post" do
-      Fabricate(:flag, post: under_flagged_post, user: other_user)
+      Fabricate(:flag_post_action, post: under_flagged_post, user: other_user)
       finder =
         ComposerMessagesFinder.new(
           user,
@@ -392,7 +392,12 @@ RSpec.describe ComposerMessagesFinder do
     it "does not show a message when the flag has already been resolved" do
       SiteSetting.dont_feed_the_trolls_threshold = 1
 
-      Fabricate(:flag, post: resolved_flag_post, user: other_user, disagreed_at: 1.hour.ago)
+      Fabricate(
+        :flag_post_action,
+        post: resolved_flag_post,
+        user: other_user,
+        disagreed_at: 1.hour.ago,
+      )
       finder =
         ComposerMessagesFinder.new(
           user,
@@ -404,8 +409,8 @@ RSpec.describe ComposerMessagesFinder do
     end
 
     it "shows a message when enough others have already flagged the post" do
-      Fabricate(:flag, post: over_flagged_post, user: other_user)
-      Fabricate(:flag, post: over_flagged_post, user: third_user)
+      Fabricate(:flag_post_action, post: over_flagged_post, user: other_user)
+      Fabricate(:flag_post_action, post: over_flagged_post, user: third_user)
       finder =
         ComposerMessagesFinder.new(
           user,
diff --git a/spec/lib/guardian/flag_guardian_spec.rb b/spec/lib/guardian/flag_guardian_spec.rb
new file mode 100644
index 00000000000..1ae97406d29
--- /dev/null
+++ b/spec/lib/guardian/flag_guardian_spec.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+RSpec.describe FlagGuardian do
+  fab!(:user)
+  fab!(:admin)
+  fab!(:flag)
+
+  describe "#can_edit_flag?" do
+    it "returns true for admin and false for regular user" do
+      expect(Guardian.new(admin).can_edit_flag?(flag)).to eq(true)
+      expect(Guardian.new(user).can_edit_flag?(flag)).to eq(false)
+    end
+
+    it "returns false when flag is system" do
+      expect(Guardian.new(admin).can_edit_flag?(Flag.system.first)).to eq(false)
+    end
+
+    it "returns false when flag was already used with post action" do
+      Fabricate(:post_action, post_action_type_id: flag.id)
+      expect(Guardian.new(admin).can_edit_flag?(flag)).to eq(false)
+    end
+
+    it "returns false when flag was already used with reviewable" do
+      Fabricate(:reviewable_score, reviewable_score_type: flag.id)
+      expect(Guardian.new(admin).can_edit_flag?(flag)).to eq(false)
+    end
+  end
+end
diff --git a/spec/lib/plugin/instance_spec.rb b/spec/lib/plugin/instance_spec.rb
index bd72cfc57b0..4488bb45207 100644
--- a/spec/lib/plugin/instance_spec.rb
+++ b/spec/lib/plugin/instance_spec.rb
@@ -673,10 +673,7 @@ TEXT
   end
 
   describe "#replace_flags" do
-    after do
-      PostActionType.replace_flag_settings(nil)
-      ReviewableScore.reload_types
-    end
+    after { PostActionType.replace_flag_settings(nil) }
 
     let(:original_flags) { PostActionType.flag_settings }
 
diff --git a/spec/lib/post_revisor_spec.rb b/spec/lib/post_revisor_spec.rb
index ffff3bcfdc7..7c669e52a66 100644
--- a/spec/lib/post_revisor_spec.rb
+++ b/spec/lib/post_revisor_spec.rb
@@ -484,7 +484,7 @@ RSpec.describe PostRevisor do
 
         post = Fabricate(:post, raw: "hello world")
 
-        Fabricate(:flag, post: post, user: user)
+        Fabricate(:flag_post_action, post: post, user: user)
 
         revisor = PostRevisor.new(post)
         revisor.revise!(
diff --git a/spec/models/flag_spec.rb b/spec/models/flag_spec.rb
new file mode 100644
index 00000000000..9f384d947e8
--- /dev/null
+++ b/spec/models/flag_spec.rb
@@ -0,0 +1,69 @@
+# frozen_string_literal: true
+
+RSpec.describe Flag, type: :model do
+  before { Flag.reset_flag_settings! }
+
+  it "has id lower than 1000 for system flags" do
+    flag = Fabricate(:flag, id: 1)
+    expect(flag.system?).to be true
+  end
+
+  it "has id greater than 1000 for non-system flags" do
+    flag = Fabricate(:flag)
+    expect(flag.system?).to be false
+    expect(flag.id).to be > 1000
+  end
+
+  it "has correct name key" do
+    flag = Fabricate(:flag, name: "CuStOm Flag!!!")
+    expect(flag.name_key).to eq("custom_flag")
+
+    flag.update!(name: "It's Illegal")
+    expect(flag.name_key).to eq("its_illegal")
+
+    flag.update!(name: "THIS IS    SPaM!+)(*&^%$#@@@!)")
+    expect(flag.name_key).to eq("this_is_spam")
+  end
+
+  it "updates post action types when created, modified or destroyed" do
+    expect(PostActionType.flag_types.keys).to eq(
+      %i[notify_user notify_moderators off_topic inappropriate spam illegal],
+    )
+    expect(ReviewableScore.types.keys).to eq(
+      %i[notify_user notify_moderators off_topic inappropriate spam illegal needs_approval],
+    )
+
+    flag = Fabricate(:flag, name: "custom")
+    expect(PostActionType.flag_types.keys).to eq(
+      %i[notify_user notify_moderators off_topic inappropriate spam illegal custom],
+    )
+    expect(ReviewableScore.types.keys).to eq(
+      %i[notify_user notify_moderators off_topic inappropriate spam illegal custom needs_approval],
+    )
+
+    flag.update!(name: "edited_custom")
+    expect(PostActionType.flag_types.keys).to eq(
+      %i[notify_user notify_moderators off_topic inappropriate spam illegal edited_custom],
+    )
+    expect(ReviewableScore.types.keys).to eq(
+      %i[
+        notify_user
+        notify_moderators
+        off_topic
+        inappropriate
+        spam
+        illegal
+        edited_custom
+        needs_approval
+      ],
+    )
+
+    flag.destroy!
+    expect(PostActionType.flag_types.keys).to eq(
+      %i[notify_user notify_moderators off_topic inappropriate spam illegal],
+    )
+    expect(ReviewableScore.types.keys).to eq(
+      %i[notify_user notify_moderators off_topic inappropriate spam illegal needs_approval],
+    )
+  end
+end
diff --git a/spec/models/trust_level3_requirements_spec.rb b/spec/models/trust_level3_requirements_spec.rb
index 5ae1c9d2089..0f96e42368f 100644
--- a/spec/models/trust_level3_requirements_spec.rb
+++ b/spec/models/trust_level3_requirements_spec.rb
@@ -359,7 +359,7 @@ RSpec.describe TrustLevel3Requirements do
       flags =
         %i[off_topic inappropriate notify_user notify_moderators spam].map do |t|
           Fabricate(
-            :flag,
+            :flag_post_action,
             post: Fabricate(:post, user: user),
             post_action_type_id: PostActionType.types[t],
             agreed_at: 1.minute.ago,
@@ -369,7 +369,7 @@ RSpec.describe TrustLevel3Requirements do
       _deferred_flags =
         %i[off_topic inappropriate notify_user notify_moderators spam].map do |t|
           Fabricate(
-            :flag,
+            :flag_post_action,
             post: Fabricate(:post, user: user),
             post_action_type_id: PostActionType.types[t],
             deferred_at: 1.minute.ago,
@@ -379,7 +379,7 @@ RSpec.describe TrustLevel3Requirements do
       _deleted_flags =
         %i[off_topic inappropriate notify_user notify_moderators spam].map do |t|
           Fabricate(
-            :flag,
+            :flag_post_action,
             post: Fabricate(:post, user: user),
             post_action_type_id: PostActionType.types[t],
             deleted_at: 1.minute.ago,
@@ -388,7 +388,7 @@ RSpec.describe TrustLevel3Requirements do
 
       # Same post, different user:
       Fabricate(
-        :flag,
+        :flag_post_action,
         post: flags[1].post,
         post_action_type_id: PostActionType.types[:spam],
         agreed_at: 1.minute.ago,
@@ -396,7 +396,7 @@ RSpec.describe TrustLevel3Requirements do
 
       # Flagged their own post:
       Fabricate(
-        :flag,
+        :flag_post_action,
         user: user,
         post: Fabricate(:post, user: user),
         post_action_type_id: PostActionType.types[:spam],
@@ -405,7 +405,7 @@ RSpec.describe TrustLevel3Requirements do
 
       # More than 100 days ago:
       Fabricate(
-        :flag,
+        :flag_post_action,
         post: Fabricate(:post, user: user, created_at: 101.days.ago),
         post_action_type_id: PostActionType.types[:spam],
         created_at: 101.days.ago,
diff --git a/spec/services/auto_silence_spec.rb b/spec/services/auto_silence_spec.rb
index b29aaa18442..bf029934784 100644
--- a/spec/services/auto_silence_spec.rb
+++ b/spec/services/auto_silence_spec.rb
@@ -72,7 +72,11 @@ RSpec.describe SpamRule::AutoSilence do
     end
 
     it "returns 0 when there is one flag that has a reason other than spam" do
-      Fabricate(:flag, post: post, post_action_type_id: PostActionType.types[:off_topic])
+      Fabricate(
+        :flag_post_action,
+        post: post,
+        post_action_type_id: PostActionType.types[:off_topic],
+      )
       expect(count).to eq(0)
     end
 
diff --git a/spec/system/composer/dont_feed_the_trolls_popup_spec.rb b/spec/system/composer/dont_feed_the_trolls_popup_spec.rb
index 4edec527dc8..70f37965442 100644
--- a/spec/system/composer/dont_feed_the_trolls_popup_spec.rb
+++ b/spec/system/composer/dont_feed_the_trolls_popup_spec.rb
@@ -6,7 +6,7 @@ describe "Composer don't feed the trolls popup", type: :system do
   fab!(:topic) { Fabricate(:topic, user: user) }
   fab!(:post) { Fabricate(:post, user: user, topic: topic) }
   fab!(:reply) { Fabricate(:post, user: troll, topic: topic) }
-  fab!(:flag) { Fabricate(:flag, post: reply, user: user) }
+  fab!(:flag) { Fabricate(:flag_post_action, post: reply, user: user) }
   let(:topic_page) { PageObjects::Pages::Topic.new }
 
   before { sign_in user }
diff --git a/spec/system/flagging_post_spec.rb b/spec/system/flagging_post_spec.rb
index 50cb7ebbb91..ea6d2c9f29f 100644
--- a/spec/system/flagging_post_spec.rb
+++ b/spec/system/flagging_post_spec.rb
@@ -12,7 +12,7 @@ describe "Flagging post", type: :system do
 
   describe "Using Take Action" do
     it "can select the default action to hide the post, agree with other flags, and reach the flag threshold" do
-      other_flag = Fabricate(:flag, post: post_to_flag, user: Fabricate(:moderator))
+      other_flag = Fabricate(:flag_post_action, post: post_to_flag, user: Fabricate(:moderator))
       other_flag_reviewable =
         Fabricate(:reviewable_flagged_post, target: post_to_flag, created_by: other_flag.user)
       expect(other_flag.reload.agreed_at).to be_nil