Is that the Grassly FISA authorization letter previously mentioned? I skimmed it, but was unable to translate the legalese.
https://www.judiciary.senate.gov/imo/media/doc/2018-05-17%20CEG%20to%20DOJ%20(Special%20Counsel%20Investigation%20&%20Regulations).pdf
Grassley May 17, 2018 Letter to Rosenstein on SC Issues - 7 page PDF