docs/reference/fidl/language/error-catalog/_fi-0129.md

## fi-0129: Unknown attribute argument {:#fi-0129}

When using an [official attribute](/docs/reference/fidl/language/attributes.md),
you cannot provide an argument that is not in its schema:

{% include "docs/reference/fidl/language/error-catalog/label/_bad.md" %}

```fidl
{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/bad/fi-0129.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}
```

If you meant to pass a different argument and got the name wrong, change it to use the correct name:

{% include "docs/reference/fidl/language/error-catalog/label/_good.md" %}

```fidl
{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/good/fi-0129-a.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}
```

Alternatively, remove the argument:

{% include "docs/reference/fidl/language/error-catalog/label/_good.md" %}

```fidl
{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/good/fi-0129-b.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}
```

This error occurs because official attributes are validated against a schema. If
FIDL allowed arbitrary arguments, they would have no effect, and it could cause
bugs by masking typos.