diff --git a/ui (gen4)/features/base.js b/ui (gen4)/features/base.js
index b612d436..4b4dee98 100755
--- a/ui (gen4)/features/base.js	
+++ b/ui (gen4)/features/base.js	
@@ -1112,18 +1112,48 @@ module.Tags = core.ImageGridFeatures.Feature({
 				this.markChanged('images', gids)
 			}],
 
-		// XXX
+		// store .tags and .tags.selected / .tags.bookmark separately from .data...
+		//
+		// XXX see if this can be automated...
 		['prepareIndexForWrite', 
 			function(res, _, full){
-				// XXX move code here from file.buildIndex(..)
-				// 		- res.raw.tags -> res.index.tags
-				// 		- ..tags.selected -> .selected
-				// 		- ..tags.bookmark -> .bookmarked
-				// XXX will need a symmetrical action to reverse all of this...
+				var changes = this.changes
+
+				if((full || changes == null || changes.tags) && res.raw.data.tags){
+					res.index.tags = res.raw.data.tags
+				}
+
+				if((full || changes == null || changes.selected) 
+						&& res.raw.data.tags
+						&& res.raw.data.tags.selected){
+					res.index.marked = res.raw.data.tags.selected
+				}
+				if((full || changes == null || changes.bookmarked) 
+						&& res.raw.data.tags
+						&& res.raw.data.tags.bookmark){
+					res.index.bookmarked = [
+						res.raw.data.tags.bookmark || [],
+						{},
+					]
+				}
+
+				// cleanup...
+				if(res.index.data && res.index.data.tags){
+					delete res.index.data.tags.selected
+					delete res.index.data.tags.bookmark
+					//delete res.index.data.tags.bookmark_data
+					delete res.index.data.tags
+				}
 			}],
 		['prepareJSONForLoad',
-			function(res){
-				// XXX
+			function(res, json){
+				res.data.tags = json.tags || {}
+
+				res.data.tags.selected = json.marked || []
+				res.data.tags.bookmark = json.bookmarked ? json.bookmarked[0] : []
+				//res.data.tags.bookmark_data = json.bookmarked ? json.bookmarked[1] : {}
+
+				res.data.sortTags()
 			}],
 	],
 })
diff --git a/ui (gen4)/imagegrid/file.js b/ui (gen4)/imagegrid/file.js
index e376e14c..fa258915 100755
--- a/ui (gen4)/imagegrid/file.js	
+++ b/ui (gen4)/imagegrid/file.js	
@@ -795,13 +795,6 @@ module.buildIndex = function(index, base_path){
 	// buildup the data object...
 	// NOTE: this is mostly to attach stuff that is stored in separate files...
 	
-	// XXX move this to tags/marks/bookmarks...
-	// .tags + bookmarks + selection...
-	d.tags = index.tags || {} 
-	d.tags.bookmark = index.bookmarked ? index.bookmarked[0] : []
-	d.tags.selected = index.marked || []
-	d.sortTags()
-
 	// .current...
 	d.current = index.current || d.current
 
@@ -909,37 +902,6 @@ function(json, changes){
 		res.data = json.data
 	}
 
-	// tags...
-	if((changes === true || changes) && json.data.tags != null){
-		// NOTE: we write the whole set ONLY if an item is true or undefined
-		// 		i.e. not false...
-		if(changes === true || changes.bookmarked){
-			res.bookmarked = [
-				json.data.tags.bookmark || [], 
-				// NOTE: this is for bookmark metadata line comments, text,
-				// 		tags, ... etc.
-				// XXX currently this is not used...
-				json.data.bookmark_data || {},
-			]
-		}
-
-		if(changes === true || changes.selected){
-			res.marked = json.data.tags.selected || []
-		}
-
-		if(changes === true || changes.tags){
-			res.tags = json.data.tags
-		}
-
-		// clean out some stuff from data...
-		if(res.data){
-			delete res.data.tags.bookmark
-			delete res.data.tags.bookmark_data
-			delete res.data.tags.selected
-			delete res.data.tags
-		}
-	}
-
 	if(changes === true || changes && changes.images === true){
 		res.images = json.images