EE and BB spectra of the 2015 and 2018 detset, half-mission, and rings (for 2018 only) maps at 100, 143, 217, and 353 GHz. The full-mission auto-spectra of the difference maps, corrected for sky fraction, and the cross-spectra between the maps are shown. The sky fraction used here is 43%. The binning is: δℓ = 1 for 2 ≤ ℓ <  30; δℓ = 5 for 30 ≤ ℓ <  50; δℓ = 10 for 50 ≤ ℓ <  160; δℓ = 20 for 160 ≤ ℓ <  1000; and δℓ = 100 for ℓ >  1000. Figure 15 shows an enlargement of part of these spectra.