Which languages the site offers, and how amounts and dates are displayed. The tab has two parts, each with its own Save button: Save Languages and Save Format.
The default language must be one of the enabled ones
At least one language must stay enabled, and the default is chosen only from the enabled languages. If you untick the language that is currently the default, the default moves to the first language still enabled. A visitor whose preference cannot be detected sees the site in the default language.
The default language also changes the provider lists
When the default language is Farsi, the SMS tab lists Iranian providers; otherwise it lists international ones. The payments section picks its recommended gateway the same way: ZarinPal for Farsi, Stripe otherwise. Stripe is hidden on Farsi installs, and SEP is shown only on Farsi installs.
So if a provider you expect is missing from a list, check the default language first.
Clean URLs
With this on, the default language is served without a URL prefix: /about instead of /en/about. Other enabled languages keep their prefix, and an old prefixed address of the default language redirects to the clean one.
Toman or rial is display only
When the currency is the Iranian rial, you can choose to show amounts in toman or rial. Amounts are always stored in rial; this choice changes no number, only how it is shown. The choice appears only while the currency is the rial.
If the default language does not match the chosen currency or calendar, a suggestion appears. Applying it only fills in the form; press Save Format to keep it.
Calendar
The site shows dates in the Gregorian or the Jalali (Persian) calendar. Picking dates in the Hijri calendar is marked as planned for a future release.
Currency and calendar may be locked
Your service provider can lock regional settings. When they are locked, saving the currency and calendar is refused with a message saying so. Language settings are not affected by the lock.
Index machine translations
A switch in the Languages card. Off (the default): text the AI wrote and nobody has approved is shown to visitors but kept out of search engines until it is marked reviewed. On: AI text counts as published straight away. See AI Translation Review.
What a second language changes
Adding a language only makes it available. Each page, post, product, course or form still has to be translated, and what visitors see in the meantime is a choice (see "How do I choose what visitors see for a page that is not translated?"). What is translated and what is not lists the parts that stay as written.