framework/widgets/ActiveField.php
public function hint($content, $options = [])
    {
        if ($content === false) {
            $this->parts['{hint}'] = '';
            return $this;
        }

        $options = array_merge($this->hintOptions, $options);
        if ($content !== null) {
            $options['hint'] = $content;
        }
        $this->parts['{hint}'] = Html::activeHint($this->model, $this->attribute, $options);

        return $this;
    }
public function hint($content, $options = [])
    {
        if ($content === false) {
            $this->parts['{hint}'] = '';
            return $this;
        }

        $options = array_merge($this->hintOptions, $options);
        if ($content !== null) {
            $options['hint'] = $content;
        }
        $this->parts['{hint}'] = Html::activeHint($this->model, $this->attribute, $options);

        return $this;
    }
Renders the hint tag.
@param string|bool $content the hint content.
If `null`, the hint will be generated via [[Model::getAttributeHint()]].
If `false`, the generated field will not contain the hint part.
Note that this will NOT be [[Html::encode()|encoded]].
@param array $options the tag options in terms of name-value pairs. These will be rendered as
the attributes of the hint tag. The values will be HTML-encoded using [[Html::encode()]].

The following options are specially handled:

- `tag`: this specifies the tag name. If not set, `div` will be used.
See also [[\yii\helpers\Html::tag()]].

@return $this the field object itself.