NUM uses unique identifiers to store and retrieve data. Domain names and email addresses are valid NUM IDs. World Wide Web addresses are not valid NUM IDs but can be resolved as NUM URIs by using num:// instead of http:// or https://.
NUM can be used to store NUM Record data of any structure and for any purpose. Use cases can be standardised through modules, each module is numbered. For example, the Contacts module (module 1) is an attempt to standardise how an organisation or individual can associate contact data with their domain name or email address. Anyone can create a module.
NUM Records are DNS TXT records written in MODL – a character-efficient plain text data serialisation format that's well suited to the DNS. Here's an example NUM Record using the Contacts module:
NUM records are identified with NUM URIs. NUM records can be structured in a similar way to webpages on the World Wide Web and retrieved using the same URI path concept. NUM URIs take the following structure: