diff --git a/rpg/rule.py b/rpg/rule.py
index aa52e4f3f89dff11a3e81a7eee2889bb6e14cff3..595d12f03e400f5db22d4592e2428561a510317f 100644
--- a/rpg/rule.py
+++ b/rpg/rule.py
@@ -310,19 +310,19 @@ def check_rule(exprule):
             core.handle_errors(to_print + "^", 2)
             ret = ""
 
-    # Bracket verif
+    # parenthesis verif
     if ret != "":
         opening = False
         if "(" not in clean_exprule:
-            core.handle_errors(", no opening bracket founded", 2, "Error")
+            core.handle_errors(", no opening parenthesis founded", 2, "Error")
             ret = ""
         else:
             for i, _ in enumerate(clean_exprule):
-                # Opening bracket
+                # Opening parenthesis
                 if clean_exprule[i] == "(":
                     # If we found another opening but no closing
                     if opening:
-                        core.handle_errors(", opening bracket founded without "
+                        core.handle_errors(", opening parenthesis founded without "
                                            "closed one at position " +
                                            str(i + 1), 2, "Error")
                         core.handle_errors(exprule, 2)
@@ -333,13 +333,13 @@ def check_rule(exprule):
                         ret = ""
                     else:
                         opening = True
-                # Closing bracket
+                # Closing parenthesis
                 if clean_exprule[i] == ")":
                     # Seems ok
                     if opening:
                         opening = False
                     else:
-                        core.handle_errors(", closing bracket founded without "
+                        core.handle_errors(", closing parenthesis founded without "
                                            "opening before at position " +
                                            str(i + 1), 2, "Error")
                         core.handle_errors(exprule, 2)
@@ -349,11 +349,11 @@ def check_rule(exprule):
                         core.handle_errors(to_print + "^", 2)
                         ret = ""
         if opening is True:
-            core.handle_errors(", an opened bracket was never closed", 2,
+            core.handle_errors(", an opened parenthesis was never closed", 2,
                                "Error")
             ret = ""
 
-    # comma verif: max two and in the same bracket system, and min one
+    # comma verif: max two and in the same parenthesis system, and min one
     if ret != "":
         if clean_exprule.count(',') > 2:
             core.handle_errors(", too many ',' founded", 2, "Error")
@@ -362,7 +362,7 @@ def check_rule(exprule):
             core.handle_errors(", no ',' founded", 2, "Error")
             ret = ""
         else:
-            # comma always closed to a bracket
+            # comma always closed to a parenthesis
             res = re.search(r"(?<!\(),(?!\))", clean_exprule)
             if res:
                 core.handle_errors(", bad comma founded at position " +
@@ -373,18 +373,18 @@ def check_rule(exprule):
                     to_print += " "
                 core.handle_errors(to_print + "^", 2)
                 ret = ""
-            # If two commas, they should be in the same bracket system
+            # If two commas, they should be in the same parenthesis system
             comma_found = False
-            closed_bracket = False
+            closed_parenthesis = False
             for i, _ in enumerate(clean_exprule):
                 # First comma
                 if clean_exprule[i] == ",":
                     comma_found = True
-                # Closing bracket before the first comma
+                # Closing parenthesis before the first comma
                 if comma_found and clean_exprule[i] == ")":
-                    closed_bracket = True
-                # If we found another comma after the closed bracket
-                if comma_found and closed_bracket and clean_exprule[i] == ",":
+                    closed_parenthesis = True
+                # If we found another comma after the closed parenthesis
+                if comma_found and closed_parenthesis and clean_exprule[i] == ",":
                     core.handle_errors(", bad comma founded at position " +
                                        str(i + 1), 2, "Error")
                     core.handle_errors(exprule, 2)
@@ -491,7 +491,7 @@ def create_rules(all_rules):
     :return: rules ready to populate an :py:class:`~rpg.enzyme.Enzyme`
     :rtype: list(:py:class:`Rule`)
 
-    This function handle ' or ' keywords, multiple brackets, sort the
+    This function handle ' or ' keywords, multiple parenthesis, sort the
     simples rules, create sub-rules, etc. The output is ready to be used
     to create an :py:class:`~rpg.enzyme.Enzyme`.
     """
@@ -508,7 +508,8 @@ def create_rules(all_rules):
         for rul in tmp_rules:
             all_rules[rul] = tmp_cut
 
-    # handle multiple "," in one bracket so we got only ONE "," per rule
+    # handle multiple "," in one parenthesis
+    #so we got only ONE "," per rule
     for tmp_rule, tmp_cut in list(all_rules.items()):
         if tmp_rule.count(",") > 1:
             # Remove this complex rule
@@ -551,7 +552,7 @@ def create_rules(all_rules):
         # Dict of pos/val of this rule
         dict_rule = {}
         for i, val in enumerate(tmp_rule):
-            # None empty brackets
+            # None empty parenthesis
             if val != '':
                 dict_rule[i - ind] = val
         # All positions except the cleaving one