DBASS stands for Database of Aberrant Splice Sites. It contains examples of variants that cause aberrant splicing by activating abnormal splice sites. This can happen either through the creation of a de novo splice site, or the activation of a pre-existing cryptic splice site.
This repo currently only contains DBASS5, i.e. donor splice sites.
See http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3013770/pdf/gkq887.pdf for details.