Added comment lines for outlier test

combine.ini

@@ -45,6 +45,20 @@ weights = True
 #> restrict merge to only certain columns: e.g. drop channel breakdown for performance
 # columns = ['tot_scale01', 'tot_scale02', 'tot_scale03', 'tot_scale04', 'tot_scale05', 'tot_scale06', 'tot_scale07']
 
+# The outlier rejection is controlled by two numbers:
+# - The threshold (something like a deviation from the mean in units of sigma;
+#   but computed in terms of the inter-quantile distances).
+#   Lowering this value will flag more points as outliers (default = 4).
+# - The highest fraction of points that are allowed to be removed.
+#   If step 1 flags too many points in a bin, adjust it dynamically to always stay below this fraction.
+#   This is a safety feature to avoid rejecting too many points (default = 0.05 = 5%).
+#
+# instead of ~4 sigma, start flagging at ~3 sigma
+#trim = (4, 0.05)
+#trim = (4, 0.08)
+#trim = (3, 0.05)
+#trim = (3, 0.08)
+
 # By default do not use the option below to allow a better suppression of outliers.
 # However, if order independence is important like when cross checking two identical
 # NNLOJET inputs against each other, e.g. from a fixed- vs. flexible-scale grid comparison,