diff --git a/PDP10/pdp10_rp.c b/PDP10/pdp10_rp.c
index 9b0ed03c..248471b4 100644
--- a/PDP10/pdp10_rp.c
+++ b/PDP10/pdp10_rp.c
@@ -470,7 +470,7 @@ MTAB rp_mod[] = {
       NULL, NULL, NULL, "Set type based on file size at attach" },
     { UNIT_AUTO,         0, "noautosize",   "NOAUTOSIZE",   
       NULL, NULL, NULL, "Disable disk autosize on attach" },
-    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={SIMH|VHD|RAW}",
+    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={AUTO|SIMH|VHD|RAW}",
       &sim_disk_set_fmt, &sim_disk_show_fmt, NULL, "Display disk format" },
     { MTAB_XTD|MTAB_VDV, 0, "ADDRESS", NULL,
       NULL, &show_addr, NULL },
diff --git a/PDP11/pdp11_hk.c b/PDP11/pdp11_hk.c
index 52cb9c30..15cfed7e 100644
--- a/PDP11/pdp11_hk.c
+++ b/PDP11/pdp11_hk.c
@@ -680,7 +680,7 @@ MTAB hk_mod[] = {
       NULL, NULL, NULL, "Set type based on file size at attach" },
     { UNIT_AUTO,         0, "noautosize",   "NOAUTOSIZE",   
       NULL, NULL, NULL, "Disable disk autosize on attach" },
-    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={SIMH|VHD|RAW}",
+    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={AUTO|SIMH|VHD|RAW}",
       &sim_disk_set_fmt, &sim_disk_show_fmt, NULL, "Set/Display disk format" },
     { MTAB_XTD|MTAB_VDV|MTAB_VALR, 0040, "ADDRESS", "ADDRESS",
       &set_addr, &show_addr, NULL, "Bus address" },
diff --git a/PDP11/pdp11_rl.c b/PDP11/pdp11_rl.c
index 113fbf14..77ea2aec 100644
--- a/PDP11/pdp11_rl.c
+++ b/PDP11/pdp11_rl.c
@@ -390,7 +390,7 @@ static const MTAB rl_mod[] = {
       NULL, NULL, NULL, "Set type based on file size at attach" },
     { UNIT_AUTO,         0, "noautosize",   "NOAUTOSIZE",   
       NULL, NULL, NULL, "Disable disk autosize on attach" },
-    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={SIMH|VHD|RAW}",
+    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={AUTO|SIMH|VHD|RAW}",
       &sim_disk_set_fmt, &sim_disk_show_fmt, NULL, "Set/Display disk format" },
     { MTAB_XTD|MTAB_VDV|MTAB_VALR, 010, "ADDRESS", "ADDRESS",
         &set_addr, &show_addr, NULL, "Bus address" },
diff --git a/PDP11/pdp11_rp.c b/PDP11/pdp11_rp.c
index 750a5770..102e1943 100644
--- a/PDP11/pdp11_rp.c
+++ b/PDP11/pdp11_rp.c
@@ -667,7 +667,7 @@ MTAB rp_mod[] = {
       NULL, NULL, NULL, "Set type based on file size at attach" },
     { UNIT_AUTO,         0, "noautosize",   "NOAUTOSIZE",   
       NULL, NULL, NULL, "Disable disk autosize on attach" },
-    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={SIMH|VHD|RAW}",
+    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={AUTO|SIMH|VHD|RAW}",
       &sim_disk_set_fmt, &sim_disk_show_fmt, NULL, "Set/Display disk format" },
     { 0 }
     };
diff --git a/PDP11/pdp11_rq.c b/PDP11/pdp11_rq.c
index 8d4accc0..628c0374 100644
--- a/PDP11/pdp11_rq.c
+++ b/PDP11/pdp11_rq.c
@@ -1090,7 +1090,7 @@ MTAB rq_mod[] = {
       &rq_set_drives, NULL, NULL, "Set Number of Drives" },
     { UNIT_NOAUTO, UNIT_NOAUTO, "noautosize", "NOAUTOSIZE", NULL, NULL, NULL, "Disable disk autosize on attach" },
     { UNIT_NOAUTO,           0, "autosize",   "AUTOSIZE",   NULL, NULL, NULL, "Enable disk autosize on attach" },
-    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={SIMH|VHD|RAW}",
+    { MTAB_XTD|MTAB_VUN|MTAB_VALR, 0, "FORMAT", "FORMAT={AUTO|SIMH|VHD|RAW}",
       &sim_disk_set_fmt, &sim_disk_show_fmt, NULL, "Set/Display disk format" },
 #if defined (VM_PDP11)
     { MTAB_XTD|MTAB_VDV|MTAB_VALR, 004, "ADDRESS", "ADDRESS",