Public Suffix List halts submissions from those seeking reprieve from iGiant's rules Share Copy Marketers frantic to preserve their ad tracking capabilities in advance of Apple's iOS 14.5 privacy restrictions have overwhelmed a volunteer-maintained database used to oversee domain names and improve web security. The Public Suffix List (PSL) is a Mozilla-founded, community-run project to provide a list of domain suffixes, from .com and .co.uk to things like github.io and pvt.k12.ma.us, that can be used to build effective top-level domains (eTLDs) that form the basis of the web's same-origin security model. eLTDs exist as a designation because top-level domains (TLDs) themselves aren't sufficient to define the scope of a site.