diff --git a/README.md b/README.md
index 05e05b9cf8a6b349d7b6c39990d877f674a336bb..28c401d5b26f82f72d48ae7ec0c6acb065941b54 100644
--- a/README.md
+++ b/README.md
@@ -58,8 +58,10 @@ flags:
 		* one parameter: Warburg coefficient {A}
 	* p: constant phase element
 		* two parameters: {Q, alpha}
-	* t: finite approximation of a transition line
-		* three parameters: capacitance, resistance, approximation order {C, R, n}
+	* t: closed transmititon line
+		* four parameters: {R, Q, a, l}
+	* o: open (reflecting) transmititon line
+		* four parameters: {R, Q, a, l}
 
 --omega: range of frequency values (in rad/s) to sweep