The codes themselves are composed of a letter (the first letter of the task code set), followed by a three-digit number. Tasks sharing the same letter and first digit belong to the same phase.
From time-to-time, the LEDES Oversight Committee (LOC), the administrative body whichthat oversees these codes, adds and changes codes. In 2007, a set of Intellectual Property codes (for patents and trademarks) were finalized and ratified. <ref>https://www.businesswire.com/news/home/20071023005247/en/Legal-Electronic-Data-Exchange-Standard-LEDES-Finalizes</ref>In 2011, a set of "eDiscovery" codes were ratified.<ref>{{Citation |last=Roach |first=Michael |date=20 Sep 2012 |title=LEDES Adds Activity, Expense to E-Discovery Billing Codes | work=EDD Update |publisher=ALM | url= http://www.eddupdate.com/2012/09/ledes-adds-activity-expense-to-e-discovery-billing-codes-.html | accessdate=27 Feb 2016 }}</ref><ref>{{Citation |title=UTBMS eDiscovery Code Set |publisher=EDRM |publication-place= |page= |url=http://www.edrm.net/projects/metrics/utbms |accessdate=27 Feb 2016 | quote=The LEDES Oversight Committee (LOC) Uniform Task Based Management System (UTBMS) eDiscovery Code Set, ratified in 2011, is based on the EDRM Metrics Code set. }}</ref> In 2015, the LOC ratified a set of Governance, Risk and Compliance codes based on the Open Compliance & Ethics Group (OCEG) GRC Capability Model.