Canceling cards and bold text

thelonius wrote:

Bold replacement effects similar to Steely Tenacity occurs even if the card is not played but discarded for example via Constant Revolution?

No. The cardtext only applies if the card is played by default.

Name: Steely Tenacity
[TR:C, POD:DTC]
Cardtype: Action/Combat
Cost: 1 blood
Discipline: Animalism/Dominate/Quietus
Requires an Anarch. Do not replace until after this action. If you would replace this card, instead you can take this card from your ash heap.
[ani] [COMBAT] Strike: hand strike or use a melee weapon strike. This strike is at +1 damage, with 1 optional press.
[dom] [ACTION] Bleed with +1 bleed.
[qui] [ACTION] +1 stealth action. Enter combat with a minion.
Artist: Peter Bergting