diff --git a/base.fgd b/base.fgd
index 40a15e9..fca5089 100644
--- a/base.fgd
+++ b/base.fgd
@@ -1267,25 +1267,27 @@
 @PointClass base(Targetname) = env_screenoverlay: 
 	"An entity that can display and control a set of screen overlays, to be displayed over the player's view. Useful for view effects like drunkenness, or teleporter afterimages, etc."
 [
-	OverlayName1(string) : "Overlay Name 1" : "" : "Name of the first overlay material to display."
+	OverlayIndex(integer) : "Overlay Index" : -1 : "If this value is set to a number between 0 and 9, this overlay will use one of Mapbase's indexed overlay slots. Overlays in different slots will display on the screen at the same time."
+	
+	OverlayName1(material) : "Overlay Name 1" : "" : "Name of the first overlay material to display."
 	OverlayTime1(float) : "Overlay Duration 1" : "1.0" : "Amount of time that the first overlay should be displayed for, after which it will begin showing the second overlay."
-	OverlayName2(string) : "Overlay Name 2" : "" : "Name of the second overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
+	OverlayName2(material) : "Overlay Name 2" : "" : "Name of the second overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
 	OverlayTime2(float) : "Overlay Duration 2" : "1.0" : "Amount of time that the second overlay should be displayed for, after which it will begin showing the third overlay."
-	OverlayName3(string) : "Overlay Name 3" : "" : "Name of the third overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
+	OverlayName3(material) : "Overlay Name 3" : "" : "Name of the third overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
 	OverlayTime3(float) : "Overlay Duration 3" : "1.0" : "Amount of time that the third overlay should be displayed for, after which it will begin showing the fourth overlay."
-	OverlayName4(string) : "Overlay Name 4" : "" : "Name of the fourth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
+	OverlayName4(material) : "Overlay Name 4" : "" : "Name of the fourth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
 	OverlayTime4(float) : "Overlay Duration 4" : "1.0" : "Amount of time that the fourth overlay should be displayed for, after which it will begin showing the fifth overlay."
-	OverlayName5(string) : "Overlay Name 5" : "" : "Name of the fifth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
+	OverlayName5(material) : "Overlay Name 5" : "" : "Name of the fifth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
 	OverlayTime5(float) : "Overlay Duration 5" : "1.0" : "Amount of time that the fifth overlay should be displayed for, after which it will begin showing the sixth overlay."
-	OverlayName6(string) : "Overlay Name 6" : "" : "Name of the sixth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
+	OverlayName6(material) : "Overlay Name 6" : "" : "Name of the sixth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
 	OverlayTime6(float) : "Overlay Duration 6" : "1.0" : "Amount of time that the sixth overlay should be displayed for, after which it will begin showing the seventh overlay."
-	OverlayName7(string) : "Overlay Name 7" : "" : "Name of the seventh overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
+	OverlayName7(material) : "Overlay Name 7" : "" : "Name of the seventh overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
 	OverlayTime7(float) : "Overlay Duration 7" : "1.0" : "Amount of time that the seventh overlay should be displayed for, after which it will begin showing the eighth overlay."
-	OverlayName8(string) : "Overlay Name 8" : "" : "Name of the eighth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
+	OverlayName8(material) : "Overlay Name 8" : "" : "Name of the eighth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
 	OverlayTime8(float) : "Overlay Duration 8" : "1.0" : "Amount of time that the eighth overlay should be displayed for, after which it will begin showing the ninth overlay."
-	OverlayName9(string) : "Overlay Name 9" : "" : "Name of the ninth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
+	OverlayName9(material) : "Overlay Name 9" : "" : "Name of the ninth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
 	OverlayTime9(float) : "Overlay Duration 9" : "1.0" : "Amount of time that the ninth overlay should be displayed for, after which it will begin showing the tenth overlay."
-	OverlayName10(string) : "Overlay Name 10" : "" : "Name of the tenth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
+	OverlayName10(material) : "Overlay Name 10" : "" : "Name of the tenth overlay material to display. If left blank, overlay displaying will finish, and this entity will consider itself done."
 	OverlayTime10(float) : "Overlay Duration 10" : "1.0" : "Amount of time that the tenth overlay should be displayed for, after which this entity will stop displaying overlays."
 
 	// Inputs