A generally imperceptiple musical interval, smaller than a schisma.
The most convenient cutoff between schismas and schisminas, for classification of commas (in definition #2 there), is at about 1.8 cents, or precisely logarithmically 1/2 of the mercator-comma: log2[(353/284)1/2] * 1200.
The tonalsoft.com website is almost entirely the work of one person: me, Joe Monzo. Please reward me for my knowledge and effort by choosing your preferred level of financial support. Thank you.