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We are talking about a list of parameters even so we need to use plural.
Even if we were talking about the instance of the Parameters object we
would have to use the capital and monospaced font.

actionpack/lib/action_controller/metal/strong_parameters.rb

@@ -240,7 +240,7 @@ def ==(other)
     end
 
     # Returns a safe <tt>ActiveSupport::HashWithIndifferentAccess</tt>
-    # representation of this parameter with all unpermitted keys removed.
+    # representation of the parameters with all unpermitted keys removed.
     #
     #   params = ActionController::Parameters.new({
     #     name: 'Senjougahara Hitagi',
@@ -259,7 +259,7 @@ def to_h
       end
     end
 
-    # Returns a safe <tt>Hash</tt> representation of this parameter
+    # Returns a safe <tt>Hash</tt> representation of the parameters
     # with all unpermitted keys removed.
     #
     #   params = ActionController::Parameters.new({
@@ -304,8 +304,8 @@ def to_query(*args)
     alias_method :to_param, :to_query
 
     # Returns an unsafe, unfiltered
-    # <tt>ActiveSupport::HashWithIndifferentAccess</tt> representation of this
-    # parameter.
+    # <tt>ActiveSupport::HashWithIndifferentAccess</tt> representation of the
+    # parameters.
     #
     #   params = ActionController::Parameters.new({
     #     name: 'Senjougahara Hitagi',