diff --git a/docs/Config_Changes.md b/docs/Config_Changes.md
index 64fd43c5..5025d9f7 100644
--- a/docs/Config_Changes.md
+++ b/docs/Config_Changes.md
@@ -6,6 +6,12 @@ All dates in this document are approximate.
 
 # Changes
 
+20210503: The gcode_macro `default_parameter_<name>` config option is
+deprecated.  Use the `params` pseudo-variable to access macro
+parameters.  Other methods for accessing macro parameters will be
+removed in the near future.  See the [Command Templates
+document](Command_Templates.md#macro-parameters) for examples.
+
 20210430: The SET_VELOCITY_LIMIT (and M204) command may now set a
 velocity, acceleration, and square_corner_velocity larger than the
 specified values in the config file.
diff --git a/docs/Config_Reference.md b/docs/Config_Reference.md
index 708b1bec..a4ad4c0a 100644
--- a/docs/Config_Reference.md
+++ b/docs/Config_Reference.md
@@ -1155,16 +1155,6 @@ G-Code macros (one may define any number of sections with a
 #   A list of G-Code commands to execute in place of "my_cmd". See
 #   docs/Command_Templates.md for G-Code format. This parameter must
 #   be provided.
-#default_parameter_<parameter>:
-#   One may define any number of options with a "default_parameter_"
-#   prefix. Use this to define default values for g-code parameters.
-#   For example, if one were to define the macro MY_DELAY with gcode
-#   "G4 P{DELAY}" along with "default_parameter_DELAY = 50" then the
-#   command "MY_DELAY" would evaluate to "G4 P50". To override the
-#   default parameter when calling the command then using
-#   "MY_DELAY DELAY=30" would evaluate to "G4 P30". The default is
-#   to require that all parameters used in the gcode script be
-#   present in the command invoking the macro.
 #variable_<name>:
 #   One may specify any number of options with a "variable_" prefix.
 #   The given variable name will be assigned the given value (parsed