The acronym for RACI stands for responsible, accountable, consultative, and informed. This method can be used in a variety of ways. RACI is the foundational responsibility matrix, the vanilla ice cream of responsibility matrices. Other variations include flavors such as peanut butter, cookies, and others. RASCI, for example, adds a fifth level to the matrix, support. This could be a senior developer working on another project but also having extensive experience with APIs. RACI charts, also known as RACI matrices, are a type of responsibility assignment matrix in project management.