Chronology is one of the bases of quaternary studies. However, the oral and printed expressions of chronological data are still hesitating and affected by scattering of the reference systems. Notations and units are often used erroneously, particularly for the BP reference, possibly inducing real errors. In this situation the information is somewhat jammed. It is necessary to get aware of these problems.
A few remarks on the quotation of chronological data for the quaternary