This report documents the forms of authority that have governed the creation and technical administration of unique identifiers for the Arpanet and Internet. To accomplish this, it documents the forms of authority that have governed: i) how the Arpanet and Internet community created unique identifiers in protocol specifications; ii) how they built the social and technical systems needed to administer these identifiers; and iii) the forms of authority through which these systems for technical administration have operated. Furthermore, this report traces the evolution of the unique identifier administration from its origins in research funded by the united states department of defense, through increasingly civilian and, ultimately, non-governmental and community-driven organizations. This transition was remarkable, both in terms of the transition to community governance, and the backdrop of rapid, and at times, exponential growth of the internet. In explaining the evolution of unique identifiers, this report begins with the arpanet, a computer network that went online in 1969 and, in the late 1970s, began serving as the first internet backbone. Internet Protocol (IP) addresses, domain names, and port numbers are examples of identifiers, which require uniqueness within certain contexts in order for the Internet to function. An important property of Internet protocols is that they promote “interoperability” between systems and software. For instance, programs created by widely differing parties for what may be different purposes still communicate with each other, because they each comply with a suite of universal Internet protocols, and do not need additional prior arrangements for compatibility.