diff --git a/docs/G-Codes.md b/docs/G-Codes.md
index 137d14ba..04efdbf2 100644
--- a/docs/G-Codes.md
+++ b/docs/G-Codes.md
@@ -811,9 +811,17 @@ The following command is available when an
 enabled.
 
 #### SET_PIN
-`SET_PIN PIN=config_name VALUE=<value> CYCLE_TIME=<cycle_time>`:
-Note - hardware PWM does not currently support the CYCLE_TIME
-parameter and will use the cycle time defined in the config.
+`SET_PIN PIN=config_name VALUE=<value> [CYCLE_TIME=<cycle_time>]`: Set
+the pin to the given output `VALUE`. VALUE should be 0 or 1 for
+"digital" output pins. For PWM pins, set to a value between 0.0 and
+1.0, or between 0.0 and `scale` if a scale is configured in the
+output_pin config section.
+
+Some pins (currently only "soft PWM" pins) support setting an explicit
+cycle time using the CYCLE_TIME parameter (specified in seconds). Note
+that the CYCLE_TIME parameter is not stored between SET_PIN commands
+(any SET_PIN command without an explicit CYCLE_TIME parameter will use
+the `cycle_time` specified in the output_pin config section).
 
 ### [palette2]