Generally speaking, yes. ICANN establishes certain restrictions (states officially accepted by the UN, other territories, domain names of less than three letters and other exceptions). The Registry, in accordance with the Established Policies may, in turn, reserve some Premium domain names, which will be made available in the future.
In order to register and renew a domain name .madrid it is necessary to meet at least one of the following requirements:
a. Be a resident of the Community of Madrid
b. Carry out occupational, personal, commercial or cultural activities in the Community of Madrid
c. Be directly or indirectly related to the Community of Madrid
Regularly, a check will be carried out in order to guarantee the compliance with the requirements. If these are not met, the owner of the domain will be notified by e-mail. If we do not receive any answer within a set time-limit and if the conditions of use of the domain are still not complied with, the domain will be suspended.
No, domains are compatible with each other and it is possible to register as many as you wish. For this purpose, the DNS will have to be adequately setup.
No, the Community of Madrid acts as the Registration Authority of the domains .madrid and you will only be able to register your domains with its certified Registrar Agents published on this WEB.