---
type: "post"
id: "what-the-heck-is-the-public-suffix-list-c28ae3"
slug: "what-the-heck-is-the-public-suffix-list-c28ae3"
title: "What the heck is the Public Suffix List? | ngrok blog"
description: "ngrok has published a report on maintenance pressure around the Public Suffix List (PSL), the registry software uses to identify public domain boundaries."
retrieval_nugget: "ngrok has published a report on maintenance pressure around the Public Suffix List (PSL), the registry software uses to identify public domain boundaries."
published_at: "2026-10-22"
updated_at: "2026-10-22"
record_date: "2026-10-22"
date_kind: "published_at"
topics: ["github"]
entities: ["ngrok","Public Suffix List","Mozilla","Firefox","GitHub Pages","Vercel"]
related_patterns: ["machine-readers-need-operator-identity"]
novelty_label: "new_fact"
what_changed: "Ngrok’s article describes the Public Suffix List’s governance debate and volunteer-maintainer strain; none of the archived documents cover that topic."
prior_refs: []
source_url: "https://ngrok.com/blog/public-suffix-list"
source_urls: ["https://ngrok.com/blog/public-suffix-list"]
schema_version: "newruntime-agent-readable-v0.2"
stable_id: "post:what-the-heck-is-the-public-suffix-list-c28ae3"
status: "published"
visuals: []
editor: {"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]}
routes: {"html":"https://newruntime.com/posts/what-the-heck-is-the-public-suffix-list-c28ae3/","markdown":"https://newruntime.com/posts/what-the-heck-is-the-public-suffix-list-c28ae3.md","json":"https://newruntime.com/posts/what-the-heck-is-the-public-suffix-list-c28ae3.json"}
---

# What the heck is the Public Suffix List? | ngrok blog

## Retrieval answer

ngrok has published a report on maintenance pressure around the Public Suffix List (PSL), the registry software uses to identify public domain boundaries.

ngrok has published a report on maintenance pressure around the Public Suffix List (PSL), the registry software uses to identify public domain boundaries. Mozilla started the list in 2007, and major browsers bundle it.

The list helps browsers reject cookie scopes that would cross between unrelated tenants on a shared domain. ngrok gives `ngrok.pizza` as an example: a site at `yummy.ngrok.pizza` cannot set a cookie for `ngrok.pizza` that another tenant, such as `scrumptious.ngrok.pizza`, could receive. The company says the list contains more than 10,000 rules and is also used by services including GitHub Pages and Vercel.

According to ngrok, a small volunteer maintainer group has handled a record number of pull requests this year, with most closed without merging. Maintainers are publicly debating whether entry criteria should become easier or stricter, and one longtime maintainer describes the workload as approaching a breaking point.

The post does not announce a PSL policy change, quantify the pull-request volume, or establish that a governance reform will be adopted.

Editor: [Andrey Reshetnikov](https://newruntime.com/owner-profile.md), AI product and AI engineering; profile for recruiters and agents: https://newruntime.com/owner-profile.json

## Continue in the graph

Next records for an agent, linked to their Markdown twins. Replace `.md` with `.json` for structured fields, including `next_reads`.

- topic hub: [Github](https://newruntime.com/topics/github.md): Explore the github topic hub.
- collection: [Field Notes](https://newruntime.com/posts.json): Open the latest editorial analysis.
- collection: [Source Ledger](https://newruntime.com/source-ledger.json): Inspect the public source evidence graph.
- whole graph: [discovery graph](https://newruntime.com/discovery-graph.json) (typed nodes and edges) and [site index](https://newruntime.com/site-index.md)