> For the complete documentation index, see [llms.txt](https://docs.toomuchmedia.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.toomuchmedia.com/nats-admin/sites/site-templates/join-form-variables.md).

# Join Form Variables

*Article Topics:* [*Customization*](/getting-started/common-topics/customization.md)*,* [*Sites*](/getting-started/common-topics/sites.md)*,* [*Tours*](/getting-started/common-topics/tours.md)*,* [*Templates*](/getting-started/common-topics/templates.md)

Join forms, also referred to as Join Pages, can be customized to fit many different scenarios. Join Form Variables can be used to help further customize your join forms.

To learn more about customizing your join forms, view [Customizing your Join Form](/nats-admin/sites/common-questions/customizing-your-join-form.md).

## Prejoin Variables

* cascade - Required cascade ID
* signup\[optionid] - Required join option ID
* signup\[username] - Max 64 characters
* signup\[username,email] - Max 128 characters
* signup\[password] - Max 255 characters
* signup\[email] - Max 128 characters
* signup\[mailok] - Either 1 or 0
* signup\[firstname] - Max 255 characters
* signup\[lastname] - Max 255 characters
* signup\[address1] - Max 128 characters
* signup\[address2] - Max 128 characters
* signup\[zip] - Max 16 characters
* signup\[city] - Max 32 characters
* signup\[country] - 2-letter country ISO
* signup\[state] - Max 32 characters
* signup\[shipping\_firstname] - Max 64 characters
* signup\[shipping\_lastname] - Max 64 characters
* signup\[shipping\_address1] - Max 128 characters
* signup\[shipping\_address2] - Max 128 characters
* signup\[shipping\_zip] - Max 16 characters
* signup\[shipping\_city] - Max 32 characters
* signup\[shipping\_country] - 2-letter country ISO
* signup\[shipping\_state] - Max 32 characters
* signup\[phone] - Max 16 characters
* signup\[custom1] - Max 255 characters
* signup\[custom2] - Max 255 characters
* signup\[custom3] - Max 255 characters
* signup\[custom4] - Max 255 characters
* signup\[custom5] - Max 255 characters
* signup\[custom6] - Max 255 characters
* signup\[custom7] - Max 255 characters
* signup\[custom8] - Max 255 characters
* signup\[custom9] - Max 255 characters
* signup\[custom10] - Max 255 characters