diff --git a/share/man/man4/asmc.4 b/share/man/man4/asmc.4
index 9b42d021e1a..e1dd4b09d64 100644
--- a/share/man/man4/asmc.4
+++ b/share/man/man4/asmc.4
@@ -1,4 +1,4 @@
-.\"-
+.\"
 .\" Copyright (c) 2007, 2008, 2009 Rui Paulo <rpaulo@FreeBSD.org>
 .\" All rights reserved.
 .\"
@@ -112,6 +112,13 @@ minimum fan speed, the minimum speed and the maximum speed
 respectively.
 .Pp
 All values are in RPM.
+.Sh POWER MANAGEMENT
+The
+.Va dev.asmc.%d.auto_poweron
+sysctl controls whether the machine automatically powers on when AC power
+is restored after an unclean power loss
+.Pq SMC key Dq AUPO .
+A value of 1 enables automatic power-on; 0 disables it.
 .Sh RAW SMC KEY ACCESS
 When the kernel is compiled with the
 .Dv ASMC_DEBUG
diff --git a/sys/dev/asmc/asmc.c b/sys/dev/asmc/asmc.c
index 5fe89d85be6..8cd7842d03f 100644
--- a/sys/dev/asmc/asmc.c
+++ b/sys/dev/asmc/asmc.c
@@ -123,7 +123,7 @@ static int 	asmc_mbp_sysctl_light_left(SYSCTL_HANDLER_ARGS);
 static int 	asmc_mbp_sysctl_light_right(SYSCTL_HANDLER_ARGS);
 static int 	asmc_mbp_sysctl_light_control(SYSCTL_HANDLER_ARGS);
 static int 	asmc_mbp_sysctl_light_left_10byte(SYSCTL_HANDLER_ARGS);
-static int	asmc_wol_sysctl(SYSCTL_HANDLER_ARGS);
+static int	asmc_aupo_sysctl(SYSCTL_HANDLER_ARGS);
 
 static int	asmc_key_getinfo(device_t, const char *, uint8_t *, char *);
 
@@ -793,14 +793,14 @@ asmc_init(device_t dev)
 	device_printf(dev, "SMC revision: %x.%x%x%x\n", buf[0], buf[1], buf[2],
 	    ntohs(*(uint16_t *)buf + 4));
 
-	/* Wake-on-LAN convenience sysctl */
+	/* Auto power-on after AC power loss (AUPO). */
 	if (asmc_key_read(dev, ASMC_KEY_AUPO, buf, 1) == 0) {
 		SYSCTL_ADD_PROC(sysctlctx,
 		    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
-		    OID_AUTO, "wol",
+		    OID_AUTO, "auto_poweron",
 		    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
-		    dev, 0, asmc_wol_sysctl, "I",
-		    "Wake-on-LAN enable (0=off, 1=on)");
+		    dev, 0, asmc_aupo_sysctl, "I",
+		    "Auto power-on after AC power loss (0=off, 1=on)");
 	}
 
 	sc->sc_nfan = asmc_fan_count(dev);
@@ -1222,7 +1222,7 @@ asmc_key_getinfo(device_t dev, const char *key, uint8_t *len, char *type)
 /*
  * Raw SMC key access sysctls - enables reading/writing any SMC key by name
  * Usage:
- *   sysctl dev.asmc.0.raw.key=AUPO   # Set key, auto-detects length
+ *   sysctl dev.asmc.0.raw.key=TC0P   # Set key, auto-detects length
  *   sysctl dev.asmc.0.raw.value      # Read current value (hex bytes)
  *   sysctl dev.asmc.0.raw.value=01   # Write new value
  */
@@ -2338,18 +2338,17 @@ asmc_mbp_sysctl_light_left_10byte(SYSCTL_HANDLER_ARGS)
 }
 
 /*
- * Wake-on-LAN convenience sysctl.
- * Reading returns 1 if WoL is enabled, 0 if disabled.
- * Writing 1 enables WoL, 0 disables it.
+ * Auto power-on after AC power loss (AUPO key).
+ * When non-zero the machine boots automatically when AC is restored
+ * after an unclean power loss.  Useful for always-on servers / home labs.
  */
 static int
-asmc_wol_sysctl(SYSCTL_HANDLER_ARGS)
+asmc_aupo_sysctl(SYSCTL_HANDLER_ARGS)
 {
 	device_t dev = (device_t)arg1;
 	uint8_t aupo;
 	int val, error;
 
-	/* Read current AUPO value */
 	if (asmc_key_read(dev, ASMC_KEY_AUPO, &aupo, 1) != 0)
 		return (EIO);
 
@@ -2358,10 +2357,7 @@ asmc_wol_sysctl(SYSCTL_HANDLER_ARGS)
 	if (error != 0 || req->newptr == NULL)
 		return (error);
 
-	/* Clamp to 0 or 1 */
 	aupo = (val != 0) ? 1 : 0;
-
-	/* Write AUPO */
 	if (asmc_key_write(dev, ASMC_KEY_AUPO, &aupo, 1) != 0)
 		return (EIO);
 
diff --git a/sys/dev/asmc/asmcvar.h b/sys/dev/asmc/asmcvar.h
index ae027ba33ae..6388fc78fb6 100644
--- a/sys/dev/asmc/asmcvar.h
+++ b/sys/dev/asmc/asmcvar.h
@@ -175,7 +175,9 @@ struct asmc_softc {
 #define ASMC_KEY_CLAMSHELL	"MSLD"	/* RO; 1 byte */
 
 /*
- * Auto power on / Wake-on-LAN.
+ * Auto power-on after AC power loss (AUPO).
+ * When set, the machine boots automatically when AC power is restored
+ * after an unclean power loss.  This is NOT Wake-on-LAN.
  */
 #define ASMC_KEY_AUPO		"AUPO"	/* RW; 1 byte */