Unofficial Skyrim Special Edition Patch

In Whiterun there are two cells: Hall of the Dead and Whiterun Catacombs. Hall of the Dead is owned by a specific NPC: Andurs. Whiterun Catacombs has no ownership set.

In Solitude there are two cells: Hall of the Dead and Solitude Catacombs. Unlike in Whiterun, both cells are marked as owned by a faction: SolitudeStyrrsHouseFaction. Factions can include multiple NPCs, but in Solitude's case the faction only includes Styrr.

The way the ownership system in the game works is confusing, so I looked into it for my own knowledge a number of years ago. The reason you're not able to take low-value items in Whiterun's Hall of the Dead is because the cell's ownership is set to an NPC instead of a faction. Specific NPC ownership will always treat items as owned regardless of relationship rank, meaning you can't take them without it counting as stealing. Faction ownership will allow you take items below a certain value if you have a relationship rank of one or greater with at least one NPC in the given faction.