Damping Matrix

• WWizards of the Coast2017-03-14
  Official Ruling
  Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keyword abilities, such as equip, are activated abilities and will have colons in their reminder text.
• WWizards of the Coast2017-03-14
  Official Ruling
  Damping Matrix’s ability affects only artifacts and creatures on the battlefield. Activated abilities that work in other zones (such as bloodrush or unearth) can still be activated. Triggered abilities (starting with “when,” “whenever,” or “at”) are unaffected.
• WWizards of the Coast2017-03-14
  Official Ruling
  A mana ability is an ability that produces mana, not an ability that costs mana.

Rulings via Scryfall