Are there some?
There are actually quite a few. I hope this link gets you there: https://apply.commonapp.org/ApplicationRequirements/PublicFile?fn=ReqGrid.pdf. Should be a chart with one of the columns headed “writing”. If “yes” appears in that column then there is a writing supplement. If not, no writing supplement. If the link doesn’t work, find it by googling “common app no writing supplement PDF”. Good luck!
Thank you @gclsports!