Hidden item stats

Examples:
* Damage type is missing even though damage types are important gameplay element
* Range information is missing for projectile weapons when such are important (e.g. grid-based games)
* Chance to block with shields if it varies with them
* Chance to hit with weapons if it varies with them; accuracy information is missing (e.g. tactical games, esp. turn-based tactical games)
* Durability when it is relevant
* Protection values or types for armor
... and so forth.

Most obvious examples are cases where no stats at all are given. Literal description of the stats can be counted as non-hidden if they're relatively accurate.

Generally this means player has to figure the items out themselves completely.