text: Several formats for citing radiocarbon results have been used since the first samples were dated. As of 2019, the standard format required by the journal Radiocarbon is as follows.
  Uncalibrated dates should be reported as ":  ±  BP", where:
  *  identifies the laboratory that tested the sample, and the sample ID
  *  is the laboratory's determination of the age of the sample, in radiocarbon years
  *  is the laboratory's estimate of the error in the age, at 1σ confidence.
  * BP stands for "before present", referring to a reference date of 1950, so that "500 BP" means the year AD 1450.
  For example, the uncalibrated date "UtC-2020: 3510 ± 60 BP" indicates that the sample was tested by the Utrecht van der Graaff Laboratorium ("UtC"), where it has a sample number of "2020", and that the uncalibrated age is 3510 years before present, ± 60 years. Related forms are sometimes used: for example, "2.3 ka BP" means 2,300 radiocarbon years before present (i.e. 350 BC), and " yr BP" might be used to distinguish the uncalibrated date from a date derived from another dating method such as thermoluminescence.
  Calibrated  dates are frequently reported as "cal BP", "cal BC", or "cal AD", again with BP referring to the year 1950 as the zero date. Radiocarbon gives two options for reporting calibrated dates. A common format is "cal  ", where:
  *  is the range of dates corresponding to the given confidence level
  *  indicates the confidence level for the given date range.
  For example, "cal 1220–1281 AD (1σ)" means a calibrated date for which the true date lies between AD 1220 and AD 1281, with a confidence level of 1 sigma, or approximately 68%. Calibrated dates can also be expressed as "BP" instead of using "BC" and "AD". The curve used to calibrate the results should be the latest available IntCal curve. Calibrated dates should also identify any programs, such as OxCal, used to perform the calibration. In addition, an article in Radiocarbon in 2014 about radiocarbon date reporting conventions recommends that information should be provided about sample treatment, including the sample material, pretreatment methods, and quality control measurements; that the citation to the software used for calibration should specify the version number and any options or models used; and that the calibrated date should be given with the associated probabilities for each range.