ROG's and RIG's. The two black circles represent redundant object groups (ROG's). Each ROG contains a set of protein sequence accessions that point to records describing the exact same sequence from the same organism. The dotted circle represents a redundant interaction group (RIG). This RIG contains a set of protein interaction accessions that point to records describing interactions between the same two proteins (ROG's). Unique identifiers for ROG's and RIG's can be calculated independently by anyone using the primary sequences of the proteins, their taxonomy identifiers and the SHA-1 algorithm.