# Constant Presets This directory contains a set of constants presets used for testing, testnets, and mainnet. A preset file contains all the constants known for its target. Later-fork constants can be ignored, e.g. ignore phase1 constants as a client that only supports phase 0 currently. ## Format Each preset is a key-value mapping. **Key**: an `UPPER_SNAKE_CASE` (a.k.a. "macro case") formatted string, name of the constant. **Value**: can be any of: - an unsigned integer number, can be up to 64 bits (incl.) - a hexadecimal string, prefixed with `0x` Presets may contain comments to describe the values. See `mainnet.yaml` for a complete example.