diff --git a/src/main/main.c b/src/main/main.c
index 9077b61..b237d73 100644
--- a/src/main/main.c
+++ b/src/main/main.c
@@ -509,6 +509,8 @@ int main(int argc, char **argv)
 	pv_state_watch_fd_set(state, opts->watch_fd);
 	pv_state_average_rate_window_set(state, opts->average_rate_window);
 
+	/* TODO: with --numeric, call a separate default format function. */
+
 	pv_state_set_format(state, opts->progress, opts->timer, can_have_eta ? opts->eta : false,
 			    can_have_eta ? opts->fineta : false, opts->rate, opts->average_rate,
 			    opts->bytes, opts->bufpercent, opts->lastwritten, opts->name);
diff --git a/src/pv/display.c b/src/pv/display.c
index 4efe379..8cee238 100644
--- a/src/pv/display.c
+++ b/src/pv/display.c
@@ -487,6 +487,8 @@ pvdisplay_bytecount_t pv_formatter_segmentcontent(char *content, pvformatter_arg
  * If --rate was given, we output the current transfer rate instead of the
  * percentage.  With --bytes as well, the rate is given after the
  * bytes/lines.
+ *
+ * TODO: replace this with a custom --format string.
  */
 static bool pv__format_numeric(pvstate_t state, pvdisplay_t display)
 {
@@ -1077,6 +1079,8 @@ bool pv_format(pvstate_t state, /*@null@ */ const char *format_supplied, pvdispl
 
 	/*
 	 * Use the numeric mode function if we're in numeric mode.
+	 *
+	 * TODO: use a custom --format string instead.
 	 */
 	if (state->control.numeric) {
 		return pv__format_numeric(state, display);
diff --git a/src/pv/format/averagerate.c b/src/pv/format/averagerate.c
index b85e5d7..17022ce 100644
--- a/src/pv/format/averagerate.c
+++ b/src/pv/format/averagerate.c
@@ -13,6 +13,8 @@
 
 /*
  * Average transfer rate.
+ *
+ * TODO: show exact number without suffix if --numeric is active.
  */
 pvdisplay_bytecount_t pv_formatter_average_rate(pvformatter_args_t args)
 {
diff --git a/src/pv/format/bufferpercent.c b/src/pv/format/bufferpercent.c
index 2916a27..752a53a 100644
--- a/src/pv/format/bufferpercent.c
+++ b/src/pv/format/bufferpercent.c
@@ -13,6 +13,8 @@
 
 /*
  * Percentage transfer buffer utilisation.
+ *
+ * TODO: show exact number without suffix if --numeric is active.
  */
 pvdisplay_bytecount_t pv_formatter_buffer_percent(pvformatter_args_t args)
 {
diff --git a/src/pv/format/bytes.c b/src/pv/format/bytes.c
index ae8da98..0a5d568 100644
--- a/src/pv/format/bytes.c
+++ b/src/pv/format/bytes.c
@@ -13,6 +13,8 @@
 
 /*
  * Number of bytes or lines transferred.
+ *
+ * TODO: show exact number without suffix if --numeric is active.
  */
 pvdisplay_bytecount_t pv_formatter_bytes(pvformatter_args_t args)
 {
diff --git a/src/pv/format/progressbar.c b/src/pv/format/progressbar.c
index 89c387e..a06ab5f 100644
--- a/src/pv/format/progressbar.c
+++ b/src/pv/format/progressbar.c
@@ -382,6 +382,8 @@ pvdisplay_bytecount_t pv_formatter_progress_bar_only(pvformatter_args_t args)
 
 /*
  * The number after the progress bar.
+ *
+ * TODO: show percentage without adornment if --numeric is active.
  */
 pvdisplay_bytecount_t pv_formatter_progress_amount_only(pvformatter_args_t args)
 {
diff --git a/src/pv/format/rate.c b/src/pv/format/rate.c
index a4fd737..0f4eba5 100644
--- a/src/pv/format/rate.c
+++ b/src/pv/format/rate.c
@@ -13,6 +13,8 @@
 
 /*
  * Transfer rate.
+ *
+ * TODO: show exact number without suffix if --numeric is active.
  */
 pvdisplay_bytecount_t pv_formatter_rate(pvformatter_args_t args)
 {
diff --git a/src/pv/format/timer.c b/src/pv/format/timer.c
index 24a24e1..722adde 100644
--- a/src/pv/format/timer.c
+++ b/src/pv/format/timer.c
@@ -13,6 +13,8 @@
 
 /*
  * Elapsed time.
+ *
+ * TODO: show as a number if --numeric is active.
  */
 pvdisplay_bytecount_t pv_formatter_timer(pvformatter_args_t args)
 {