It indicates the date when the parchment was made, but not the date when the VM was written.
I have written two previous articles on statistics and the interpretation of results obtained from AMS measurements of C BP years to AD years using the tree ring curve.
There are three carbon isotopes that occur as part of the Earth's natural processes; these are carbon-12, carbon-13 and carbon-14.
Typically (6): The above list is not exhaustive; most organic material is suitable so long as it is of sufficient age and has not mineralised - dinosaur bones are out as they no longer have any carbon left.AMS (accelerator mass spectrometry) is used to determine the age of milligram samples of historical objects.This equipment was used at the University of Arizona (U of A) radiocarbon dating laboratory to date four of the Voynich Manuscript’s (VM) parchment pages.The graph below is a plot of 2004 tree ring data points (blue dots) used to date the VM.The y-axis is the measured BP age and the x-axis is the calculated BP age (x = 1950 - tree ring age) in 5-year intervals(III). The measured BP age ranges from 646 to 415 (231) years is condensed to 70 years (570-500).