2007-02-01 : The named card can be cast face down.

2007-02-01 : Voidstone Gargoyle stops activated abilities that are mana abilities from being activated, unlike Pithing Needle.

2007-02-01 : You can name either half of a split card, but not both. If you do so, that half (and both halves, if the split card has fuse) can’t be cast. The other half is unaffected.

2007-07-15 : Activated abilities of copies of a spell with that name (such as Lightning Storm) cannot be activated.

2016-06-08 : Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keywords are activated abilities and will have colons in their reminder text.