Artifacts with unexplained properties are classified by any attribute which has been discovered.
Delta
The Delta classification is for artifacts which offer the ability to travel, usually accompanies either Sigma or Tau classifications.
Mu
Artifacts classified with the symbol Mu have supernatural properties which have no known source of power but impact the physical world in ways which are generally described as magical.
Sigma
The artifacts with a Sigma classification as having the ability to manipulate space in some way. Bending the fabric of space and altering its dimension, shape, or the position of an object or person within space.
Tau
Tau artifacts are classified with the ability to alter the flow of time or an object or items position within the stream of time, altering how time takes its effect on an object, person, or the artifact itself.
Upsilon
Artifacts with the Upsilon classification are the most dangerous, as it symbolizes artifacts that are still largely unknown. Upsilon artifacts are kept under strict security protocols.
Omega
Artifacts with the Omega classification have incredibly dangerous potential for harm and kept under strict security protocols.