# hooks-field-buf-len

Hook API [sto_subfield](https://xrpl-hooks.readme.io/v2.0/reference/sto_subfield) requires non-empty input buffer.

This check warns about empty input in calls to `sto_subfield` (if it's specified by a constant - variable parameter is ignored).

[Read more](https://xrpl-hooks.readme.io/v2.0/docs/serialized-objects)