I will keep a number either 11 digits or 15 digits or 16 digits

[mdnurnabi]

I will keep a number either 11 digits or 15 digits or 16 digits. How to do it?

[wroos]

Hello,
You should use a text type field with appearance numbers and a regex constraint. See examples in the support documentation
https://support.kobotoolbox.org/restrict_responses.html?highlight=regex
or with (the recommended) search function of this forum
https://community.kobotoolbox.org/search?q=limit%20digits%20regex%20numbers%20enter

[Kal_Lam]

@mdnurnabi, maybe this post discussed previously should help you solve your issue as outlined by @wroos:

Restrict for Entering 10, 13 OR 17 digit number only

Try changing the above to either of the two Option 1 regex(., ‘^[0-9]{10}$’) or regex(., ‘^[0-9]{13}$’) or regex(., ‘^[0-9]{17}$’) Option 2 regex(., ‘^([0-9]{10}|[0-9]{13}|[0-9]{17})$’)