Q164: How can I allow users to change the language of the reservation form when using advanced integration?

By default the reservation form contains a language selection drop-down so users can choose a language. If you already have language selection elsewhere on the webpage, you can remove this drop-down in the reservation templates (in settings / integrate with my site).

You can also pass the lang parameter to the URL containing the ibookfishing module. The value is a two-letter language code, e.g. EN, DE, FR, IT, ES. If you don't pass the language parameter, the default language specified in the settings of the ibookfishing module will be used.