> Aztec.nr API reference, v6.0.0 (mainnet and testnet). Index: https://docs.aztec.network/aztec-nr-api/v6.0.0/llms.txt

# Global ARCHIVE_HEIGHT

Module: `protocol_types::constants`

```rust
pub global ARCHIVE_HEIGHT: u32;
```

Convention for constant array lengths are mainly divided in 2 classes:

- FUNCTION CALL
- TRANSACTION

Agreed convention is to use MAX_XXX_PER_CALL resp. MAX_XXX_PER_TX, where XXX denotes a type of element such as commitment, or nullifier, e.g.,:

- MAX_NULLIFIERS_PER_CALL
- MAX_NOTE_HASHES_PER_TX

In the kernel circuits, we accumulate elements such as note hashes and the nullifiers from all functions calls in a transaction. Therefore, we always must have: MAX_XXX_PER_TX >= MAX_XXX_PER_CALL

For instance: MAX_NOTE_HASHES_PER_TX >= MAX_NOTE_HASHES_PER_CALL MAX_NULLIFIERS_PER_TX >= MAX_NULLIFIERS_PER_CALL