The MODERN working group will define a set of Internet-based mechanisms for the purposes of managing and resolving telephone numbers (TNs) in an IP environment. Devices, applications, and network tools increasingly need to manage TNs, including requesting and acquiring TN delegations from authorities. The output of the working group should make distribution, acquisition, and management of TNs simpler for all entities involved. The working group will define an information management framework for the roles and functions involved in associating information with one or more TNs in an IP environment. The working group will also identify protocol mechanisms to support the interactions between the functions defined by the framework. This includes either recommending or defining protocol mechanisms for acquiring, associating and resolving TNs, with a preference for use of existing protocol mechanisms. TNs may either be managed in a hierarchical tree, or in a distributed registry. The protocol mechanism for acquiring TNs will provide an enrollment process for the entities that use and manage TNs. The protocol mechanism for resolving TNs will allow entities such as service providers, devices, and applications to access data related to TNs. Maintaining reliability, real-time application performance, and security and privacy for both the data and the protocol interactions are primary considerations. The working group will take into consideration existing IETF work including STIR, ENUM, SPEERMINT, DRINKS and SCIM. The work of this group will focus on TNs, as defined in RFC3966, and blocks of TNs, that are used to initiate communication with another user of a service. There is an expectation that aspects of the architecture and protocols defined by the working group will be reusable for other user-focused identifiers. Any such extensions or reuse of MODERN mechanisms are out of scope for the MODERN working group. Solutions and mechanisms created by the working group will be flexible enough to accommodate different policies for TN assignment and management, for example those established by different regulatory agencies. The working group will deliver the following: - An architecture overview, including high level requirements and security/privacy considerations - A description of the enrollment processes for existing and new TNs including any modifications to metadata related to those TNs - A description of protocol mechanisms for accessing contact information associated with enrollments - A description of mechanisms for resolving information related to TNs