One important category is concentrated sources of platform knowledge which many people struggle to acquire (The mnemonic medium is particularly well suited to platform knowledge). For example:
Outside of platform knowledge, our understanding of the applications of the mnemonic medium is much weaker (How might the mnemonic medium enable readers in genres outside platform knowledge?).
A canonical use must also be authored virtuosically, not just in the prose but also in the prompts. See What are the most important attributes of good spaced repetition memory prompts?