In the string representation of a ParameterSet, constrained parameters were notated with a \* symbol in the far left.
In version 2.3, this is replaced with a C. Parameters that are read-only for other reasons (i.e. exposed model parameters) are noted with an R.
In [1]:
import phoebe
In [2]:
b = phoebe.default_binary()
In [3]:
print(b.filter(qualifier=['sma', 'incl', 'asini']))