Hi, efvain - 

The "Reference Only" designation is as designed by the state agency (https://www.state.nj.us/treasury/taxation/pdf/current/cbt/cbt100.pdf).  When NJ mandated the electronic filing of CBT-100 and CBT-100S in 2019, the watermark was added to prevent the filing of mailed returns.  It is not something ProSeries or you can remove.

Stephanie