SCP stands for Secure, Contain, and Protect. It originated from a web game created to get people interested in science fiction writing.
The Foundation is not currently known for anything related to the number three. Until this discovery, it was believed that the only SCP objects present at Site 19 were SCP-1020 (a package of germinated seeds) and the bulk of the biological hazards held in Sector 4’s Biological Research Laboratories. The new information suggests that there may be more than one type of sentient being contained at Site-19. Further research is required to identify any other instances related to this anomaly if they exist.
However, it has been speculated that if a specimen exists then it must not be an ordinary SCP object as we would know it. It must be an SCP-001 listed anomaly and therefore not known to the Foundation at all. This unknown SCP is likely the cause of SCP: Containment Breach as well as other unexplained containment breaches or failures on record.