SCP Handbook: Secure. Contain. Protect.

=CLASSES=

Each SCP has an 'Object class'. The class refers to how strong the anomaly/creature is. There are three Primary classes, two Secondary classes and one Esoteric class. Each one is dangerous and pose a threat but some are less dangerous than others.

PRIMARY CLASS
Safe:
SCPs classed as safe are anomalies that are sufficiently understood or completely and reliably contained. SCPs can also be classed as safe when the anomalous effect it possesses has been completely neutralised or can only be intentionally activated by an SCP worker. Classifying an anomaly as Safe, however, does not mean that handling or activating it does not pose a threat, and personnel are to be reminded that all safety protocols are to be observed at all times.

Euclid:
Euclid-class objects are anomalies that are either insufficiently understood or inherently unpredictable, such that reliable containment is not always possible, but do not pose sufficient threat to qualify for Keter classification. The vast majority of anomalies cataloged and contained by the Foundation are initially classified as Euclid until they are either sufficiently understood or exhibit sufficient danger to qualify for reclassification. In particular, any anomaly that exhibits autonomy, sentience and/or sapience is generally classified a Euclid-class entity at minimum, due to the inherent unpredictability of an object that can act or think on its own.

Keter:
Keter-class objects are SCPs that pose a threat to the safety of SCP personnel and the rest of mankind and either require extensive and complex procedures to contain or cannot be fully contained by the Facilities current technology and knowledge.These anomalies are generally considered the most dangerous ones in the SCP Foundation containment, and all research efforts are directed towards enabling more reliable containment of such anomalies or, as a last resort, the neutralisation or destruction of said anomalies.

SECONDARY CLASS
Neutralised:
Neutralized anomalies are those that are no longer anomalous, either through having been intentionally or accidentally destroyed, disabled, or otherwise no longer function or exhibit anomalous effects. The documentation for Neutralised anomalies is archived for the future in case the anomaly regains its anomalous properties or otherwise recurs.

Explained:
anomalies classed as explained are those that are completely and fully understood to the point where their effects are now explainable by mainstream science, have been debunked as a false or mistaken classification, or are so widespread and publicly disseminated such that containment is no longer possible.

ESOTERIC CLASS
Thaumiel:
Thaumiel-class objects are highly classified and extremely rare anomalies that are utilised by the Foundation to contain or counteract the effects of other highly dangerous anomalies, especially Keter-class objects. Even the mere existence of Thaumiel-class objects is classified at the highest levels of the Foundation and their locations, functions, and current status are unknown to those without clearance. Thaumiel class objects pose a threat to mankind and staff at SCP.