s3xmodit is format primarily used for OHBs which allows for the submission of any of these tracker modules:

.s3m
.xm
.mod
.it

Thus, "s3xmodit!"

This category grants Mixist points. For large battles however, module categories are usually grouped by size (8k, 32k, ect...) but will still accept any of the above mentioned modules. For size based formats, categories less than 64k will grant Chipist points.