diff --git a/docs/02.devguides/47.extensions/page.md b/docs/02.devguides/47.extensions/page.md
index c965cb3..c0a8b4b 100644
--- a/docs/02.devguides/47.extensions/page.md
+++ b/docs/02.devguides/47.extensions/page.md
@@ -13,6 +13,8 @@ You can find publicly available extensions on [Forgebox](https://forgebox.io/typ
 
 Extensions live under the `/application/extensions` folder within your Preside application, each extension with its own folder, e.g.
 
+_(as of Preside 10.27, you are also able to create extensions in an `/extensions_app`. Great for separating locally committed extensions for organising your application's code.)_
+
 ```
 /application
     ...
@@ -21,9 +23,12 @@ Extensions live under the `/application/extensions` folder within your Preside a
         /my-extension-2
         /my-extension-3
         ...
-    ...
+    /extensions_app
+        /my-app-extension-1
+        ...
 ```
 
+
 Each extension can then contain *all of the valid convention-based folders that your application can contain*, i.e. `/handlers`, `/services`, `/i18n`, `/preside-objects`, etc.:
 
 ```
diff --git a/docs/02.devguides/53.adminenvheader/page.md b/docs/02.devguides/53.adminenvheader/page.md
new file mode 100644
index 0000000..90737d8
--- /dev/null
+++ b/docs/02.devguides/53.adminenvheader/page.md
@@ -0,0 +1,45 @@
+---
+id: adminenvheader
+title: Admin development environment banner header
+---
+
+## Overview
+
+As of Preside 10.27, you are able to have the admin user interface display a banner showing the working environment (i.e. staging vs production).
+
+## Configuring the banner
+
+In Config.cfc, you are able to configure whether or not the banner shows + configure an icon, alert class + optionally configure a specific message to display:
+
+```luceescript
+settings.environmentMessage = "Some message to display"; // default is empty, using i18n approach as detailed below
+settings.environmentBannerConfig = {
+    icon     = "fa-code"
+  , cssClass = "alert-info"
+  , display  = true
+};
+```
+
+Using this approach, you can use [Coldbox environments system](https://coldbox.ortusbooks.com/getting-started/configuration/coldbox.cfc/configuration-directives/environments) to provide different configuration for different environments. i.e. Have "local", and "staging" environment configurations by using corresponding methods in your Config.cfc:
+
+```luceescript
+function local() {
+  super.local();
+
+  settings.environmentBannerConfig = { display=false };
+}
+
+function staging() {
+  settings.environmentBannerConfig = { display=true, icon="fa-code", cssClass="alert-warning" };
+  // ...
+}
+```
+
+## Using i18n for the message
+
+If you leave `settings.environmentMessage` empty, then you can use i18n to specify the message. The key for the i18n resource will be: `cms:environment.#environment#.label`, where `environment` is the coldbox environment. So in `/i18n/cms.properties`, you could have:
+
+```properties
+environment.staging.label=This is the staging environment
+environment.dev.label=This is the dev environment
+```
\ No newline at end of file
diff --git a/docs/02.devguides/53.features/page.md b/docs/02.devguides/53.features/page.md
new file mode 100644
index 0000000..7ae4c4f
--- /dev/null
+++ b/docs/02.devguides/53.features/page.md
@@ -0,0 +1,225 @@
+---
+id: features
+title: Feature flagging
+---
+
+## Overview
+
+Preside has a concept of feature flags that can be used to turn on and off various features of the core platform and of your extensions. It is important to note, that these are designed to be specified **in code**  and effect the fundamental makeup of your application including its database structure. They are **not** feature flags that can be turned on and off for a running application.
+
+## Definition
+
+Feature flags are defined in your application/extension's `Config.cfc` file in a `settings.features` struct. The keys of this struct are the IDs of the feature flags. Each feature flag value is a structure with the following keys:
+
+```luceescript
+settings.features.myfeature = {
+    enabled       = true                     // the only required key, whether or not the feature is enabled
+  , dependsOn     = [ "featurex" ]           // as of Preside 10.27, features can depend on other features. If any parent is disabled, this feature will be disabled
+  , widgets       = [ "widgetx", "widgety" ] // an array of widget IDs that should only be available when this feature is enabled
+  , siteTemplates = [ "*" ]                  // if using site templates, can specify which site templates have this feature enabled
+};
+```
+
+## Disabling/enabling a feature
+
+If Preside core, or any extension defines a feature that you would like to override, then you will need to override the enabled property for that feature in your _application's_ Config.cfc file. e.g.
+
+```luceescript
+settings.features.admin.enabled        = false;
+settings.features.websiteUsers.enabled = false;
+
+settings.features.somneExtensionFeature.enabled  = true;
+```
+
+## Checking whether or not a feature is enabled
+
+From handlers and views, Preside offers a helper function, `isFeatureEnabled( feature )`. In services that make use of the [[presidesuperclass]], you have a `$isFeatureEnabled( feature )` helper. Examples:
+
+```luceescript
+// in a handler or view
+if ( isFeatureEnabled( "myFeature"  ) ) {
+  // something
+}
+
+// in a service
+if ( $isFeatureEnabled( "myCoolFeature" ) ) {
+  // something
+}
+
+// as of Preside 10.26
+if ( isFeatureEnabled( "feature1 or ( feature2 and feature3 )" ) ) {
+  // something
+}
+```
+
+## Limiting functionality using features
+
+The general approach to applying feature flags is to decorate your code with `@feature` annotations. Depending on the source code file type, the way you annotate will differ. The core Preside platform allows you to flag the following resource types:
+
+* Preside objects
+* Preside object properties
+* Forms, tabs, fieldsets and fields
+* Widgets
+* Handlers (as of Preside 10.27)
+* Views (as of Preside 10.27)
+* Services (as of Preside 10.27)
+
+_Note: Various extensions may also use their own feature flagging approaches to their resources._
+
+### Preside objects & their properties
+
+To feature flag a Preside object, annotate the `component` directive with either of the following approaches:
+
+```luceescript
+/**
+ * Approach one. Using @ in javadoc style block
+ *
+ * @feature somefeature
+ */
+component {
+  // ...
+}
+```
+
+```luceescript
+component feature="approach2Feature" {
+  // ...
+}
+```
+
+Feature flagging properties is a case of adding a `feature` attribute to the property:
+
+
+```luceescript
+component {
+  property name="asset" relationship="many-to-one" relatedto="asset" feature="assetManager";
+}
+```
+
+### Forms, tabs, fieldsets and fields
+
+Documentation for feature flagging forms can be found here: [[presideforms-features]]. In essence, however, you can add `feature` attributes to the `form`, `tab`, `fieldset` and `field` elements:
+
+```xml
+<form feature="myfeature">
+  <tab id="tab1" feature="myfeaturex">
+    <fieldset id="fs1" feature="myfeaturey">
+      <field name="somefield" feature="myfeaturez" />
+      <!-- ... -->
+    </fieldset>
+    <!-- ... -->
+  </tab>
+  <!-- ... -->
+</form>
+```
+
+### Widgets
+
+Due to widgets being definable in multiple ways, widgets must be specified in the feature flag struct in Config.cfc. i.e.
+
+```luceescript
+settings.features.someFeature = { enabled=true, widgets=[ "widget1", "widget3" ] };
+```
+
+Note: if you want to add a widget to a feature that is defined elsewhere, you should use something like the following approach:
+
+```luceescript
+// ensure widgets array exists and then *append* to it
+// rather than overwriting it completely which may destroy existing
+// feature widget definitions
+settings.features.featurex.widgets = settings.features.featurex.widgets ?: [];
+ArrayAppend( settings.features.featurex.widgets, "my-new-widget" );
+```
+
+### Handlers & services
+
+As of Preside 10.27, handlers and services may be feature flagged. If the feature is disabled, the service/handler will then not be enabled. The benefit of this, is that handlers and services will not be loaded into memory if their feature flag is disabled. Annotating a handler CFC is the same as annotating a preside object, i.e.
+
+```luceescript
+/**
+ * Approach 1, javadoc comment style
+ *
+ * @feature        someFeature || anotherfeature
+ * @presideservice true
+ * @singletone
+ */
+component {
+  // ...
+}
+```
+
+Or:
+
+```luceescript
+component feature="someFeature || anotherfeature" {
+  // ...
+}
+```
+
+#### Wirebox injections
+
+If you have a service that depends on another service that is feature flagged, you may use the `featureInjection` dsl to avoid issues. For example:
+
+
+```luceescript
+/**
+ * @singleton      true
+ * @presideService true
+ */
+component {
+
+  // featureInjection allows injection of a singleton without
+  // any errors when the feature is disabled
+  property name="aFeatureSpecificService" inject="featureInjection:myfeature:AFeatureSpecificService";
+
+  // ...
+  function someFunction() {
+    // always do a feature check before attempting
+    // to use the service - otherwise you will get errors
+    // when the feature is not enabled and the service does not exist
+    if ( $isFeatureEnabled( "myFeature" ) ) {
+      aFeatureSpecificService.doSomething();
+    }
+  }
+
+
+}
+```
+
+### Views
+
+As of Preside 10.27, a view may be feature flagged. This has the benefit of avoiding loading the view into memory when it is not used. To feature flag a view **the first line** of the `.cfm` file must add an annotation in the following form:
+
+```lucee
+<!---@feature myFeature--->
+```
+
+## .presideIgnore.json file
+
+As of Preside 10.27, you may find that you have a `.presideIgnore.json` file in the root of your project. This file is used by Preside in production to ignore files that are feature flagged with features that are disabled. This avoids the system ever having to read the files and can be a useful strategy to improve startup times and resource usage of your applications when running with a lot of disabled features.
+
+### Controlling use of the feature
+
+By _default_, the application will **write** to this file in local mode and **read** from the file in production mode. This allows you to optimize production and have your local development environment maintain the content of the file.
+
+To control this feature, use the following in your application's Config.cfc file:
+
+```luceescript
+// local mode
+settings.ignoreFile.read  = false;
+settings.ignoreFile.write = true;
+
+// production mode
+settings.ignoreFile.read  = true;
+settings.ignoreFile.write = false;
+
+// completely disabled
+settings.ignoreFile.read  = false;
+settings.ignoreFile.write = false;
+```
+
+### Strategy for use
+
+If using this feature, you should have your application run with "local mode" at least once to generate the ignore file **before** the code makes it to production. This could be simply running the application locally in your production branch and committing the resultant `.presideIgnore.json` file, or having this run as a warmup routine in a docker build in a pipeline or similar.
+
+If in doubt and experiencing issues with this feature, you are perfectly safe to disable it.
\ No newline at end of file
diff --git a/docs/02.devguides/chapter.md b/docs/02.devguides/chapter.md
index 1063e71..035b257 100644
--- a/docs/02.devguides/chapter.md
+++ b/docs/02.devguides/chapter.md
@@ -15,6 +15,7 @@ In this chapter, you should find detailed guides on developing with the Preside
 * [[workingwiththericheditor]]
 * [[datamanager]]
 * [[routing]]
+* [[features]]
 * [[cmspermissioning]]
 * [[websiteusersandpermissioning]]
 * [[editablesystemsettings]]
@@ -54,3 +55,4 @@ In this chapter, you should find detailed guides on developing with the Preside
 * [[selectdataviews]]
 * [[customdbmigrations]]
 * [[systemalerts]]
+* [[adminenvheader]]
diff --git a/docs/06.upgradenotes/10-27/page.md b/docs/06.upgradenotes/10-27/page.md
new file mode 100755
index 0000000..5c78c9f
--- /dev/null
+++ b/docs/06.upgradenotes/10-27/page.md
@@ -0,0 +1,16 @@
+---
+id: 10-26-upgrade-notes
+title: Upgrade notes for 10.26 -> 10.27
+---
+
+## Summary
+
+The 10.27 release is mostly focused on better feature flagging in the core product. With this in mind, you will need to take some extra care when upgrading.
+
+## Feature flagging
+
+Prior to 10.27, many preside objects and services were available to the application, even when their features were not in use. From 10.27 onwards, extra effort is made to ensure that all parts of the system are appropriately feature flagged. This means that the system should run with fewer resources and create fewer database tables than before, especially when you have many disabled features.
+
+The potential downside to this is that you may inadvertently be referencing services, handlers, views and objects that will no longer be available and your application will complain of missing resources. These will need to be tested and you **should never directly upgrade a production environment without testing first**.
+
+Read the [[features]] documentation to familiarise yourself with the new feature flagging changes in Preside 10.27.
\ No newline at end of file