Index: game/modules/tome/class/PlayerDisplay.lua
===================================================================
--- game/modules/tome/class/PlayerDisplay.lua	(revision 2620)
+++ game/modules/tome/class/PlayerDisplay.lua	(working copy)
@@ -292,6 +292,9 @@
 		local e = player.tempeffect_def[eff_id]
 		local dur = p.dur + 1
 		local desc = e.long_desc(player, p)
+		if e.on_merge then
+			desc = desc.." (can merge)"
+		end
 		if e.status == "detrimental" then
 			self:mouseTooltip(desc, self:makeTexture(("#LIGHT_RED#%s(%d)"):format(e.desc,dur), x, h, 255, 255, 255)) h = h + self.font_h
 		else