diff --git a/ui/crop.js b/ui/crop.js
index 056e875e..c14d754b 100755
--- a/ui/crop.js
+++ b/ui/crop.js
@@ -325,7 +325,7 @@ function filterImagesDialog(){
 				+'All filter text fields support\n'
 				+'regular expressions.\n'
 				+'\n'
-				+'Adding a "!" to any text filter\n'
+				+'Prepending a "!" to any text filter\n'
 				+'will negate it, selecting unmatching\n'
 				+'images only.\n'
 				+'\n'
diff --git a/ui/data.js b/ui/data.js
index f90698ec..07bbf938 100755
--- a/ui/data.js
+++ b/ui/data.js
@@ -1491,11 +1491,16 @@ function makePrevFromListAction(get_closest, get_list, restrict_to_ribbon){
 //
 // XXX also need a date filter -- separate function?
 // XXX need a number filter with support of advanced comparisons...
+// XXX add functions as patterns...
 function filterGIDs(filter, gids, data, images){
 	images = images == null ? IMAGES : images
 	gids = gids == null ? getLoadedGIDs(null, data) : gids
 
 	// normalize filter...
+	// 	in format:
+	// 		<attr>: <pattern>
+	// 	out format:
+	// 		<attr>: [ <regexp>, <expected-match-result> ]
 	for(var k in filter){
 		if(typeof(filter[k]) == typeof('str')){
 			if(filter[k][0] == '!'){