The type argument specifies whether regular minimality or
  regular maximality is to be checked.  "probability.different"
  and "percent.same" are for datasets in the
  probability-different and percent-same formats, and imply regular
  minimality and regular maximality checks, respectively.
  "reg.minimal" and "reg.maximal" can be specified to
  force checking for regular minimality and regular maximality,
  respectively, independent of the used dataset.  In particular,
  "reg.minimal" and"reg.maximal" are to be used for
  datasets that are properly in the general format.  check.regular calls check.data.  In
  particular, the rows and columns of the canonical
  representation matrix (see Value) are canonically
  relabeled based on the labeling provided by
  check.data.  That is, using the
  check.data labeling, the pairs of points of subjective
  equality (PSEs) are assigned identical labels, leaving intact the
  labeling of the rows and relabeling the columns with their
  corresponding PSEs.  If the data X do not satisfy regular
  minimality/maximality, check.regular produces respective
  messages.  The latter give information about parts of X
  violating that condition.
  Regular minimality/maximality is a fundamental property of
  discrimination and means that 
  
-  every row contains a single minimal/maximal entry;
    
-  every column contains a single minimal/maximal entry;
    
-  an entry $p\_ij$ of Xwhich is 
      minimal/maximal in the $i$th row is also minimal/maximal
      in the $j$th column, and vice versa.
  If $p\_ij$ is the entry which is minimal/maximal in
  the $i$th row and in the $j$th column, the
  $i$th row object (in one, the first, observation area) and
  the $j$th column object (in the other, the second,
  observation area) are called each other's PSEs.  In psychophysical
  applications, for instance, observation area refers to the two fixed
  and perceptually distinct areas in which the stimuli are presented
  pairwise; for example, spatial arrangement (left versus right) or
  temporal order (first versus second).