Primary Enclosure Designations:
These are the most common Enclosure Designations used in AEP articles, and make up the bulk of the objects. The other ED's are highly classified and used only for specific anomalies. (e.g. contests, tales)
Oriens
Oriens-class AEPs are anomalies that are easily and safely enclosed. This is often due to the fact that the Association has researched the AEP well enough that containment does not require significant resources or that the anomalies require a specific and conscious activation or trigger. Classifying an AEP as Oriens, however, does not mean that handling or activating it does not pose a threat. For example, AEP-002 is designated "Oriens", but is still extremely dangerous.
Meridien
Meridien-class AEPs are anomalies that require more resources to enclose completely or where containment isn't always reliable. Usually, this is because the anomaly is insufficiently understood or inherently unpredictable. Meridien is the Enclosure Designation with the greatest scope, and it's usually a safe bet that an AEP will be this class if it doesn't easily fall into any of the other standard Object Classes. As a note, any AEP that is sentient and/or sapient is generally classified as Meridien, due to the inherent unpredictability of an object that can act or think on its own.
Noctis
Noctis-class AEPs are anomalies that are exceedingly difficult to contain consistently or reliably, with containment procedures often being extensive and complex. The Association often cannot contain these AEPs well due to not having a solid understanding of the anomaly, or lacking the technology to properly contain or counter it. A Noctis AEP does not always mean the AEP is dangerous, just that it is simply very difficult or costly to contain.
Special Object Classes:
Neutralized
Neutralized AEPs are anomalies that have either been fully understood, exhibit no more anomalous properties, or destroyed. Neutralized AEPs pose no danger to the Association.
Theta
Theta-class AEPs are anomalies that are extremely dangerous to the Association and the world, and are very difficult to contain. Usually, this is because the anomaly is insufficiently understood or inherently unpredictable. Only a small portion of all AEP anomalies are classified Theta, and Theta classification must be approved by a Regional Administrator. Theta-Class anomalies are restricted to Division-IV and V Personnel only.