# HEADER_CRIT

> `const` **HEADER\_CRIT**: `2` = `2`

Defined in: [packages/filecoin-encryption-envelope/src/cose/constants.ts:24](https://github.com/FilOzone/synapse-sdk/blob/9ad84d812e1dd635b76420a7d9388555a04f31b6/packages/filecoin-encryption-envelope/src/cose/constants.ts#L24)

`crit`, RFC 9052 §3.1. Names header labels a processor must understand and
act on. For the acceptance rule see CriticalHeaderError.