adds notes

src/Umbraco.Core/Services/LocalizedTextServiceExtensions.cs

@@ -64,6 +64,15 @@ namespace Umbraco.Core.Services
 
         private static ICultureDictionary _cultureDictionary;
 
+        /// <summary>
+        /// TODO: We need to refactor how we work with ICultureDictionary - this is supposed to be the 'fast' way to
+        /// do readonly access to the Dictionary without using the ILocalizationService. See TODO Notes in `DefaultCultureDictionary`
+        /// Also NOTE that the ICultureDictionary is based on the ILocalizationService not the ILocalizedTextService (which is used
+        /// only for the localization files - not the dictionary)
+        /// </summary>
+        /// <param name="manager"></param>
+        /// <param name="text"></param>
+        /// <returns></returns>
         internal static string UmbracoDictionaryTranslate(this ILocalizedTextService manager, string text)
         {
             var cultureDictionary = CultureDictionary;

src/Umbraco.Web/Dictionary/UmbracoCultureDictionary.cs

@@ -18,6 +18,11 @@ namespace Umbraco.Web.Dictionary
     /// <summary>
     /// A culture dictionary that uses the Umbraco ILocalizationService
     /// </summary>
+    /// <remarks>
+    /// TODO: The ICultureDictionary needs to represent the 'fast' way to do dictionary item retrieval - for front-end and back office.
+    /// The ILocalizationService is the service used for interacting with this data from the database which isn't all that fast 
+    /// (even though there is caching involved, if there's lots of dictionary items the caching is not great)
+    /// </remarks>
 	public class DefaultCultureDictionary : Umbraco.Core.Dictionary.ICultureDictionary
 	{
 	    private readonly ILocalizationService _localizationService;