> For the complete documentation index, see [llms.txt](https://docs.emaildelivery.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.emaildelivery.com/docs/what-to-know-before-using-the-email-marketing-platform/contact-lists-use-a-flexible-architecture.md).

# Contact lists use a flexible architecture

You don't need to specify whether a property is a date, phone number, currency, has a decimal, a phone number, is alphanumeric, a boolean, or any other restriction.

As long as your data is in CSV format, it will be accepted; all you need to do is give it a name. 

If you use another delimiter such as ; instead of , your contact list will be rejected.