Confidence levels for errors or upper limits can be specified
in two ways. A simple number is interpreted as a percentage
confidence level and converted into a probability from a one-
tailed distribution. By adding "sigma", or any abbreviation
of it to the number, the value of probability for 1 sigma
(
68%) is multiplied by that number. For example,
User Input Probability
90.0 0.1
99 0.01
3 sigma 1.1446e-5
5 sigma 5.5788e-13
This input method is used for the FERL and PERL parameters.