There are a number of spells that deal non-preventable damage. Wish, for example, states:
The stress of casting this spell to produce any effect other than duplicating another spell weakens you. After enduring that stress, each time you cast a spell until you finish a long rest, you take 1d10 necrotic damage per level of that spell. This damage can't be reduced or prevented in any way.
However, this non-preventable damage is worded as "This damage can't be reduced or prevented in any way". Damage reduction and damage prevention are AFAIK both specific mechanics that are more or less standardized, with spells, feats and equipment that grant these effects explicitly using these words.
It feels to me like non-preventable damage only stops effects that are explicitly worded as "reduces damage taken" or "prevent all damage taken", and that effects that use other words to affect the damage taken by the player may actually be able to stop the damage. For example, AFAIK D&D 5E has both damage reduction and damage resistance. However, I don't know if this is a correct interpretation.
So the question I have is: does "reduced or prevented" in this case explicitly refer to effects worded using the words "reduces damage taken" or "prevent all damage taken", or do they also refer to other effects that reduce or prevent damage with other words?