Safe

Safe-class creatures are anomalies that are easily and safely contained. This is often due to the fact that the Foundation has researched the anomaly well enough that containment does not require significant resources or that the anomalies require a specific and conscious activation or trigger. Classifying an anomaly as Safe, however, does not mean that handling or activating it does not pose a threat.

Euclid

Euclid-class creatures are anomalies that require more resources to contain completely or where containment isn't always reliable. Usually this is because the anomaly is insufficiently understood or inherently unpredictable. Euclid is the Object Class with the greatest scope, and it's usually a safe bet that an anomaly will be this class if it doesn't easily fall into any of the other standard Object Classes.

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Keter

Keter-class threats are anomalies that are exceedingly difficult to contain consistently or reliably, with containment procedures often being extensive and complex. The Foundation often can't contain these well due to not having a solid understanding of the anomaly, or lacking the technology to properly contain or counter it. anomalies does not mean the anomaly is dangerous, just that it is simply very difficult or costly to contain.

Thaumiel

Thaumiel-class creatures are anomalies that the Foundation specifically uses to contain other anomalies. 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 known to few Foundation personnel outside of the O5 Council.

Apollyon

Apollyon-class threats are anomalies that cannot be contained, are expected to breach containment imminently, or some other similar scenario. Such anomalies are usually associated with world-ending threats or a K-Class Scenario of some kind, and require a massive effort from the Foundation to deal with.

Archon

Archon-class threats are anomalies that could theoretically be contained but are best left uncontained for some reason. Archon anomalies may be a part of consensus reality that is difficult to fully contain, or may have adverse effects if put into containment. These anomalies are not uncontainable - the defining feature of the class is that the Foundation chooses to not put the anomaly into containment.

Cernunnos

Cernunnos-class anomalies could be functionally contained, but for logistical or ethical reasons the Foundation has chosen not to at this time. The anomaly may still be partially contained or actively concealed from the public, but the costs of fully containing it are deemed to outweigh the benefits.

Ticonderoga

Ticonderoga-class anomalies cannot be contained, but also do not need to be contained. While these anomalies are similar to Archon-class in that their containment is unnecessary, Ticonderoga-class are distinguished by also not being containable given the Foundation's current knowledge and resources. This may be due to their widespread or ubiquitous occurrence on Earth, despite the general public remaining unaware of their existence or anomalous nature.

Explained

Explained anomalies were formerly classified as anomalies before being completely and fully understood, to the point where their effects are now explainable by mainstream science, or were falsely identified as an anomaly before being debunked as a hoax or misunderstanding. While most of these articles are listed separately as Explained anomalies, a mainlist anomaly may be reclassified as Explained after further investigation into the apparent anomaly.

Neutralized

Neutralized anomalies were classified as anomalies but are no longer anomalous, due to the object being intentionally or accidentally destroyed or disabled, or simply due to its anomalous properties or effects ceasing.

Decommissioned

Decommissioned anomalies are anomalies that have been intentionally destroyed or stripped of their anomalous properties by the horizon Foundation. As the Foundation usually tries to contain rather than neutralize anomalous objects, this object class is only used when it is not possible to fully contain an anomaly, or when excessive expenditure of resources is required to keep an anomaly in containment. Decommissioning may also be performed for ethical reasons, particularly when containment necessitates extreme suffering or is unable to prevent excessive loss of life. To avoid any unnecessary losses, decommissioning anomalies requires authorization from a higher authority, such as the O5 Council, the Ethics Committee, or the Decommissioning Department.

Pending

anomalies that have not yet been assigned an object class may be labelled as Pending. This is used to indicate that the Foundation does not currently have enough information to assign an object class to the anomaly. This is a deliberate decision to emphasize that research is ongoing, and is not the same as the author simply not knowing which object class to assign!

Uncontained

anomalies that are not yet contained may be assigned an object class, often Keter, but in some articles Uncontained is used in place of an object class to emphasize that ongoing effort is required to establish or restore containment.