Added some comments for clarity

Author: RoyTheunissen

Scripts/Editor/Core/CollectionItemDropdown.cs

@@ -37,6 +37,7 @@ public CollectionItemDropdown(AdvancedDropdownState state, Type targetItemType,
                 if (!string.IsNullOrEmpty(options.ValidateMethod))
                     validationMethod = owner.GetType().GetMethod(options.ValidateMethod, new[] {itemType});
 
+                // If it's specified that a callback should be fired when an item is selected, cache that callback.
                 if (!string.IsNullOrEmpty(options.OnSelectCallbackMethod))
                 {
                     onSelectCallbackMethod = owner.GetType().GetMethod(options.OnSelectCallbackMethod,

Scripts/Editor/PropertyDrawers/SOCItemPropertyDrawer.cs

@@ -216,6 +216,8 @@ private void DrawCollectionItemDropDown(
             bool canUseDropDown = true;
             bool isDropdownError = false;
 
+            // If the options are meant to be constrained to a specific collection, check if the collection specified
+            // is valid. If not, draw some useful messages so you're aware what's wrong and know how to fix it.
             if (!string.IsNullOrEmpty(OptionsAttribute.ConstrainToCollectionField))
             {
                 SerializedProperty collectionField = property.serializedObject.FindProperty(