Group refers to the basic kind of animal that likely made the trackway: V stands for vertebrate trackway or trace, while I stands for invertebrate trackway or trace. For UCM numbers < 542, these judgments are based mainly on the inspections of professional ichnologists given in the trackway datasheet compiled by Prescott, from Track Meets 1 and 2. However, for UCM numbers > 542, there was little such interpretation made and the group is based on inspection of the photographs only by Buta, who used the TM 1 and 2 interpretations as a guide for the other specimens. The group is preliminary in these cases and subject to revision as needed. The group is probably more reliable than the ichnotaxon classifications in column 4 for some specimens. However, some are guesses. The symbols :,? (used, for example, as V? or I:) represent different degrees of uncertainty, with ? being a guess.

A few other groups listed in this column:
VM - a "mushy" vertebrate trackway (where little detail is seen in obvious footprints)
IM - a "mushy" invertebrate trackway
M - a "mushy" trackway of uncertain nature
GB - a set of gas escape or gas bubble impressions, superficially resembling raindrop impressions
WT - a weak trackway
CR - crater
x or ? - something of uncertain interpretation