I'm using this module in the form of a website, together with the webform module and webform phone.
In this form I have two fields for phones: one for fixed phones and other to mobile phones.
Some people use this form by entering the mobile number phone in both fields.
In my country, the first number of mobile phone starts with 7, 8 or 9, so I wonder if there is the possibility of creating a rule where in the field for fixed phone could not be started with the numbers 7, 8 and 9 as the first number of the phone.
Any help is welcome.