diff --git a/go/reg-test/expected/case-cli-help.sh.out b/go/reg-test/expected/case-cli-help.sh.out
index 0f268dd00..416b6351d 100644
--- a/go/reg-test/expected/case-cli-help.sh.out
+++ b/go/reg-test/expected/case-cli-help.sh.out
@@ -234,6 +234,33 @@ which is the same as:
 Usage: ./reg-test/../../go/mlr sort-within-records [options]
 Outputs records sorted lexically ascending by keys.
 
+================================================================
+Usage: ./reg-test/../../go/mlr step [options]
+Computes values dependent on the previous record, optionally grouped by category.
+-a {delta,rsum,...}   Names of steppers: comma-separated, one or more of:
+-f {a,b,c} Value-field names on which to compute statistics
+-g {d,e,f} Optional group-by-field names
+-F         Computes integerable things (e.g. counter) in floating point.
+-d {x,y,z} Weights for ewma. 1 means current sample gets all weight (no
+           smoothing), near under under 1 is light smoothing, near over 0 is
+           heavy smoothing. Multiple weights may be specified, e.g.
+           "./reg-test/../../go/mlr step -a ewma -f sys_load -d 0.01,0.1,0.9". Default if omitted
+           is "-d 0.5".
+-o {a,b,c} Custom suffixes for EWMA output fields. If omitted, these default to
+           the -d values. If supplied, the number of -o values must be the same
+           as the number of -d values.
+
+Examples:
+  ./reg-test/../../go/mlr step -a rsum -f request_size
+  ./reg-test/../../go/mlr step -a delta -f request_size -g hostname
+  ./reg-test/../../go/mlr step -a ewma -d 0.1,0.9 -f x,y
+  ./reg-test/../../go/mlr step -a ewma -d 0.1,0.9 -o smooth,rough -f x,y
+  ./reg-test/../../go/mlr step -a ewma -d 0.1,0.9 -o smooth,rough -f x,y -g group_name
+
+Please see https://miller.readthedocs.io/en/latest/reference-verbs.html#filter or
+https://en.wikipedia.org/wiki/Moving_average#Exponential_moving_average
+for more information on EWMA.
+
 ================================================================
 Usage: ./reg-test/../../go/mlr tac
 Prints records in reverse order from the order in which they were encountered.
diff --git a/go/todo.txt b/go/todo.txt
index 497d030a2..39b4aecbb 100644
--- a/go/todo.txt
+++ b/go/todo.txt
@@ -1,8 +1,9 @@
 ----------------------------------------------------------------
 TOP OF LIST:
 
-! johnkerl/miller/... -> readthedocs in all usage messages
+! mlr step iterate
 ! mlrrc
+! dsl `any` type w/ doc
 ! gating after: 'int x = 1; x = "abc"'
 ! verb skeletons
 ! auxents iterate