diff --git a/src/docs/user/configuration/custom_fields.diviner b/src/docs/user/configuration/custom_fields.diviner
--- a/src/docs/user/configuration/custom_fields.diviner
+++ b/src/docs/user/configuration/custom_fields.diviner
@@ -101,6 +101,8 @@
   - **default**: Default field value.
   - **strings**: Allows you to override specific strings based on the field
     type. See below.
+  - **instructions**: Optional block of remarkup text which will appear
+    above the control when rendered on the edit view.
 
 The `strings` value supports different strings per control type. They are:
 
diff --git a/src/infrastructure/customfield/field/PhabricatorCustomField.php b/src/infrastructure/customfield/field/PhabricatorCustomField.php
--- a/src/infrastructure/customfield/field/PhabricatorCustomField.php
+++ b/src/infrastructure/customfield/field/PhabricatorCustomField.php
@@ -1063,6 +1063,17 @@
   /**
    * @task edit
    */
+  public function getInstructionsForEdit() {
+    if ($this->proxy) {
+      return $this->proxy->getInstructionsForEdit();
+    }
+    return null;
+  }
+
+
+  /**
+   * @task edit
+   */
   public function renderEditControl(array $handles) {
     if ($this->proxy) {
       return $this->proxy->renderEditControl($handles);
diff --git a/src/infrastructure/customfield/field/PhabricatorCustomFieldList.php b/src/infrastructure/customfield/field/PhabricatorCustomFieldList.php
--- a/src/infrastructure/customfield/field/PhabricatorCustomFieldList.php
+++ b/src/infrastructure/customfield/field/PhabricatorCustomFieldList.php
@@ -108,6 +108,12 @@
 
     foreach ($enabled as $field_key => $field) {
       $field_handles = array_select_keys($handles, $phids[$field_key]);
+
+      $instructions = $field->getInstructionsForEdit();
+      if (strlen($instructions)) {
+        $form->appendRemarkupInstructions($instructions);
+      }
+
       $form->appendChild($field->renderEditControl($field_handles));
     }
   }
diff --git a/src/infrastructure/customfield/standard/PhabricatorStandardCustomField.php b/src/infrastructure/customfield/standard/PhabricatorStandardCustomField.php
--- a/src/infrastructure/customfield/standard/PhabricatorStandardCustomField.php
+++ b/src/infrastructure/customfield/standard/PhabricatorStandardCustomField.php
@@ -211,6 +211,10 @@
     $this->setFieldValue($value);
   }
 
+  public function getInstructionsForEdit() {
+    return $this->getFieldConfigValue('instructions');
+  }
+
   public function renderEditControl(array $handles) {
     return id(new AphrontFormTextControl())
       ->setName($this->getFieldKey())