Browsers, and the browser engines that power them, provide critical public infrastructure to over five billion people. To cover the high cost of maintaining such complex feats of engineering, browser vendors and search engine providers have improvised a system in which money is levied from search revenue and distributed to browsers. Over the years, this ad hoc system has succeeded in providing some funding to browsers but it suffers from a muddled lack of transparency and has known detrimental effects on funding attribution, concentration, search quality, privacy, misinformation, publisher revenue, and opinion pluralism. This specification captures the web community's experience with the current system so as to refine requirements and formalizes a browser/search levy that improves on the current one and addresses its shortcomings.