Plenty of CDISC rules compare one dataset against another - an adverse event
date against the subject's reference dates in DM, a visit against the trial
design. Hand over a single dataset and those questions cannot be answered.
coreval does not guess. Those rules are skipped, and $skipped names the
dataset each one wanted. Running them anyway would compare your data against
columns that are not there and report problems that do not exist.
Most rules still run - across AE, DM, LB and VS, 76-84% of the applicable
ones work on a single dataset. But the ones that cannot are the cross-dataset
checks, which are often the ones that matter.
So a short $findings table here does not mean the data is clean. It is
a quick first pass, not a verdict. Run check_study() on the whole folder
before drawing conclusions.