# require_valid_auth_flags · FT4 Rell API · Chromia Docs (concept)

> function require_ valid_ auth_ flags(flags: list<text>) Checks that all flags values passed are composed of letters and/or underscores. Throws "INVALID FLA

Source: https://docs.chromia.com/pages/ft4-rell/-f-t4-library/lib.ft4.core.accounts/require_valid_auth_flags/

FUNCTION

# require\_valid\_auth\_flags

```signature
function require_valid_auth_flags(flags: list<text>)
```

[Source](https://gitlab.com/chromaway/ft4-lib/-/blob/development/rell/src/lib/ft4/core/accounts/auth_flags_config.rell#lines-69)

Checks that all flags values passed are composed of letters and/or underscores.

Throws `"INVALID FLAGS"` if any flag does not match `/[a-z_A-Z]+/`

[View this page on docs.chromia.com](https://docs.chromia.com/pages/ft4-rell/-f-t4%20-library/lib.ft4.core.accounts/require_valid_auth_flags.html)Generated API reference, mirrored from the live docs