# 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/bc8a4b093324ccef9b407251fcf4e91823c6f599/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.