diff --git a/image_analysis/structure_refinement/SolventSites.cpp b/image_analysis/structure_refinement/SolventSites.cpp
index ddabc266b..5b2240e78 100644
--- a/image_analysis/structure_refinement/SolventSites.cpp
+++ b/image_analysis/structure_refinement/SolventSites.cpp
@@ -17,7 +17,7 @@
 namespace {
 
 constexpr double PI = 3.14159265358979;
-constexpr double SEARCH_RADIUS = 6.0;        // A: ion pairs are listed out to it (Cat_Wiz)
+constexpr double SEARCH_RADIUS = 6.0;        // A: ion pairs are listed out to it, as Cat_Wiz lists them
 constexpr double SHELL_RADIUS = 3.4;         // A: the N and O neighbours listed and typed
 // A: the ligands bond valences are summed over, following Echols et al. (2014) Acta Cryst. D70, 1104-1114
 constexpr double BVS_RADIUS = 3.5;
@@ -44,8 +44,9 @@ constexpr double R0_N[BVS_CATIONS] = {1.85, 1.93, 2.26, 2.14};
 // and to N with its spread where the papers give one (Mg only: elsewhere the band is all there is, esd 0), the N
 // and O it cannot have nearer than `too_close`, an exclusion zone [exclude_lo, exclude_hi) it keeps empty (Mg
 // only), its charge and electrons, and its row in SolventSite::bvs (-1 none).
-// Bands following Cat_Wiz, Naleem et al. (2026) Nucleic Acids Res. 54, gkag120; and Leonarski et al. (2017)
-// Nucleic Acids Res. 45, 987-1004, (2019) RNA 25, 173-192, (2025) Nucleic Acids Res. 53, gkae1148
+// Coordination bands following Naleem et al. (2026) Nucleic Acids Res. 54, gkag120 (Cat_Wiz)
+// Distances and exclusion zone following Leonarski et al. (2017) Nucleic Acids Res. 45, 987-1004, (2019) RNA 25,
+// 173-192 and (2025) Nucleic Acids Res. 53, gkae1148
 struct SpeciesRule {
     double lo, hi;
     double ideal, esd, ideal_n, esd_n;