Public Comment

Public Comment is a vital part of our multistakeholder model. It provides a mechanism for stakeholders to have their opinions and recommendations formally and publicly documented. It is an opportunity for the ICANN community to effect change and improve policies and operations.

closed Draft NCAP Study 2 Report and Responses to Questions Regarding Name Collisions



The Name Collision Analysis Project (NCAP) Discussion Group received seven (7) comments to this proceeding.

The NCAP Discussion Group has now begun a thorough review of the Public Comment submissions as it prepares its final Study 2 report and responses to the ICANN Board questions. The NCAP Discussion Group will submit its final NCAP Study 2 documents to the SSAC for its consideration. The Security and Stability Advisory Committee (SSAC) will then submit the documents to the ICANN Board along with any associated SSAC advice.

What We Received Input On

The Name Collision Analysis Project (NCAP) Discussion Group is seeking input to two documents:

  1. Draft NCAP Study 2 report
  2. Detailed responses to the Board’s questions regarding name collisions as outlined in resolution 2017.11.02.30 and re-affirmed in resolution 2021.03.25.13.

Draft NCAP Study 2 Report

This report is structured to guide the reader through the methodology and significant findings of three pivotal research studies, as well as the analysis of the NCAP Discussion Group's extensive work activities. This material is what informs the eleven strategic recommendations provided at the end of the report.

One of the key recommendations is the establishment of a new workflow, the Name Collision Risk Assessment Workflow, designed to enhance the assessment process of new generic top-level domains (gTLDs). This recommendation underscores the NCAP Discussion Group’s belief that name collisions should be approached not merely as a technical challenge but as a critical risk management issue.

Responses to Board Questions

This document contains the NCAP Discussion Group’s detailed responses to the Board’s nine questions related to the definition of name collision, user experience and possible harm, causes of collisions, potential risks, and possible mitigations, among other topics related to name collisions.

Proposals For Your Input
Draft NCAP Study 2 Report (pdf, 1.39 MB)
Detailed responses to the Board’s questions as outlined in resolution 2017.11.02.30 and re-affirmed in resolution 2021.03.25.13 (pdf, 257.69 KB)


Name Collision refers to the situation where a name that is defined and used in one namespace may also appear in another (see the proposed definition of Name Collisions published by the Security and Stability Advisory Committee). Users and applications intending to use a name in one namespace may actually use it in a different one, and unexpected behavior may result where the intended use of the name is not the same in both namespaces. The circumstances that lead to a name collision could be accidental or malicious.

On 2 November 2017, the ICANN Security and Stability Advisory Committee (SSAC) was tasked by the ICANN Board in resolutions 2017.11.02.29 - 2017.11.02.31 to:

  • Conduct a study to present data, analysis and points of view, and provide advice to the Board regarding the risks posed to users and end systems if .CORP, .HOME, .MAIL strings were to be delegated in the root, as well as possible courses of action that might mitigate the identified risks.
  • Conduct a study to present data, analysis and points of view and provide advice to the Board on a series of questions regarding name collisions.

The SSAC responded with a proposal for three consecutive studies intended to address the Board's requests. In April 2019, the NCAP Discussion Group was formed to allow interested members of the ICANN community to participate in the NCAP effort.

The final NCAP Study 1 report, published on 19 June 2020, documented prior work on name collisions and assessed name collision datasets. In response to the findings of Study 1, the NCAP Discussion Group proposed a redesign of the proposed Study 2 to adjust the study goals, and have the NCAP Discussion Group undertake most of the work slated for paid contractors in the original version of the Study 2 proposal. On 3 March 2021, the ICANN Board directed the NCAP Discussion Group to proceed with Study 2 as redesigned.

On 22 January 2022, the NCAP Discussion Group published for Public Comment two draft work products that contribute to the Study 2 work:

  • A Perspective Study of DNS Queries for Non-Existent Top-Level Domains: The study’s main objective is to provide insights and guidance for future examinations of the DNS name collision data that will be used by ICANN for risk analysis and assessments of TLD string applications.
  • Case Study of Collision Strings: Case studies of .corp, .home, .mail, .internal, .lan, and .local using DNS query data from A and J root servers. The case studies highlight changes over time of the properties of DNS queries and traffic alterations as a result of DNS evolution.

The NCAP Discussion Group presented at dedicated sessions at ICANN74, ICANN75, ICANN76, ICANN77 and ICANN78 to ensure the broader community was aware of its work, findings, and pending recommendations.