Update README.md

README.md

@@ -290,7 +290,7 @@ altered — and asks whether the model assigns higher log-likelihood to the orig
 ### `syn_human` · `syn_mouse` — Synonymous codon substitution (20,000 pairs each)
 
 Codons within a real CDS are replaced with the highest-frequency synonym for the target
-species (`recoding_mode = "optimize"`, `optimization_rate = 1.0`), while the upstream and
+species, while the upstream and
 downstream flanking sequence is left unchanged. Amino acid identity is preserved by
 construction. The model should prefer the natural codon usage over the artificially
 optimised variant.