# HEADER_UNKNOWN_KEY

> an SQL header line with a name croft does not know

**Error** · category **project** (the project has a mistake in an asset file, croft.json or the command line) · exit **2** (invalid project or usage)

An SQL header line with a name croft does not know.

The header of an SQL asset is the run of `-- name: value` lines at the top of the file, and it takes four
names: description, key, check and warn. A line such as `-- chek: amount >= 0` has a colon after its first
word, so croft reads it as a header line, and chek is none of the four. The rest of the header still counts.

What to do:
- A misspelled name: apply the fix, which renames it to the name it is closest to (chek → check).
- A plain comment that happens to start with "word:": reword it without the colon after the first word
  (-- Note that ... rather than -- Note: ...).
- The header is only the lines at the very top, before any SQL. A -- key: or -- check: line further down is not
  part of it: move it up into the header.

[`croft docs sql`](https://croft.zabaca.com/docs/guides/sql.md) describes the whole file, and [`croft docs checks`](https://croft.zabaca.com/docs/guides/checks.md) the check language.

The same page is in the CLI: `croft docs HEADER_UNKNOWN_KEY`.

Source: https://croft.zabaca.com/docs/reference/errors/header-unknown-key/