Document fortress maintenance cost in info Hvy-Plastic

diff --git a/info/Hvy-Plastic.t b/info/Hvy-Plastic.t
index 92b635ff30fced36924160fc9683a16bc79c1624..b1aea5d7ccdd45862797bba7fd594be46450c881 100644 (file)
--- a/info/Hvy-Plastic.t
+++ b/info/Hvy-Plastic.t
@@ -21,6 +21,8 @@ command?
 .s1
 Infrastructure is disabled.
 .s1
+Fortresses cost maintenance, like capitals.
+.s1
 Your refineries make less petrol from each barrel of oil than usual.
 .s1
 Natural resources gold, oil and uran deplete much slower than usual.