4 Oct 2004
Can be placed on artifacts with no or zero activation costs, but this has no effect on them. It does not increase the cost to one.
4 Oct 2004
Only affects the generic mana part of activation costs. Colored parts of mana costs are not affected.
15 Jul 2006
Can't reduce Snow mana costs.
8 Jun 2016
Activated abilities contain a colon. They're generally written "[Cost]: [Effect]." Some keywords are activated abilities and will have colons in their reminder text.