Knowledge of Shapes

Spells with this trait increase the severity of your oracular curse when cast. Usually, only revelation spells have this trait. You can't cast a cursebound spell if you don't have an oracular curse. A cursebound ability that allows a defense uses your spell attack modifier or spell DC unless noted otherwise.

This indicates abilities from the oracle class.

Spellshape actions tweak the properties of your spells. You must use a spellshape action directly before casting the spell you want to alter. If you use any action (including free actions and reactions) other than casting a spell directly after, you waste the benefits of the spellshape action. The benefit is also lost if your turn ends before you cast the spell. Any additional effects added by a spellshape action are part of the spell's effect, not of the spellshape action itself.