diff --git a/doc/rasctl.1 b/doc/rasctl.1
index cf16da96..93c8d436 100644
--- a/doc/rasctl.1
+++ b/doc/rasctl.1
@@ -12,7 +12,7 @@ rasctl \- Sends management commands to the rascsi process
 [\fB\-v\fR]
 \fB\-i\fR \fIID\fR
 [\fB\-c\fR \fICMD\fR]
-[\fB\-f\fR \fIFILE\fR]
+[\fB\-f\fR \fIFILE|PARAM\fR]
 [\fB\-n\fR \fINAME\fR]
 [\fB\-t\fR \fITYPE\fR]
 [\fB\-u\fR \fIUNIT\fR]
@@ -79,8 +79,8 @@ eject, protect and unprotect are idempotent.
 .BR \-b\fI " " \fIBLOCK_SIZE
 The optional block size. For SCSI drives 512, 1024, 2048 or 4096 bytes, default size is 512 bytes. For SASI drives 256 or 1024 bytes, default is 256 bytes.
 .TP
-.BR \-f\fI " " \fIFILE
-Path to the disk image file. See the rascsi(1) man page for allowable file types.
+.BR \-f\fI " " \fIFILE|PARAM
+Device-specific: Either a path to a disk image file, or a parameter for a non-disk device. See the rascsi(1) man page for permitted file types.
 .TP 
 .BR \-t\fI " " \fITYPE
 Specifies the device type. This type overrides the type derived from the file extension of the specified image. See the rascsi(1) man page for the available device types. For some types there are shortcuts (only the first letter is required):
diff --git a/doc/rasctl_man_page.txt b/doc/rasctl_man_page.txt
index bed9750c..a02916b6 100644
--- a/doc/rasctl_man_page.txt
+++ b/doc/rasctl_man_page.txt
@@ -7,7 +7,7 @@ NAME
 
 SYNOPSIS
        rasctl  -l  | -s | [-g LOG_LEVEL] [-h HOST] [-p PORT] [-r RESERVED_IDS]
-       [-v] -i ID [-c CMD] [-f FILE] [-n NAME] [-t TYPE] [-u UNIT]
+       [-v] -i ID [-c CMD] [-f FILE|PARAM] [-n NAME] [-t TYPE] [-u UNIT]
 
 DESCRIPTION
        rasctl Sends commands to the rascsi process to make  configuration  ad‐
@@ -75,14 +75,15 @@ OPTIONS
               bytes,  default  size  is 512 bytes. For SASI drives 256 or 1024
               bytes, default is 256 bytes.
 
-       -f FILE
-              Path to the disk image file. See the rascsi(1) man page for  al‐
-              lowable file types.
+       -f FILE|PARAM
+              Device-specific: Either a path to a disk image file, or a param‐
+              eter  for a non-disk device. See the rascsi(1) man page for per‐
+              mitted file types.
 
        -t TYPE
-              Specifies  the device type. This type overrides the type derived
+              Specifies the device type. This type overrides the type  derived
               from  the  file  extension  of  the  specified  image.  See  the
-              rascsi(1)  man  page  for  the  available device types. For some
+              rascsi(1) man page for the  available  device  types.  For  some
               types there are shortcuts (only the first letter is required):
                  hd: SCSI hard disk drive
                  rm: SCSI removable media drive
@@ -92,16 +93,16 @@ OPTIONS
                  daynaport: DaynaPORT network adapter
 
        -n VENDOR:PRODUCT:REVISION
-              The vendor, product and revision for the device, to be  returned
+              The  vendor, product and revision for the device, to be returned
               with the INQUIRY data. A complete set of name components must be
               provided. VENDOR may have up to 8, PRODUCT up to 16, REVISION up
               to 4 characters. Padding with blanks to the maxium length is au‐
-              tomatically applied. Once set the name of  a  device  cannot  be
+              tomatically  applied.  Once  set  the name of a device cannot be
               changed.
 
        -u UNIT
-              Unit  number  (0  or  1). This will default to 0. This option is
-              only used when there are multiple SCSI devices on a shared  SCSI
+              Unit number (0 or 1). This will default to  0.  This  option  is
+              only  used when there are multiple SCSI devices on a shared SCSI
               controller. (This is not common)
 
 EXAMPLES
diff --git a/src/raspberrypi/rasctl.cpp b/src/raspberrypi/rasctl.cpp
index fddd1901..28a8dd3e 100644
--- a/src/raspberrypi/rasctl.cpp
+++ b/src/raspberrypi/rasctl.cpp
@@ -541,7 +541,7 @@ int main(int argc, char* argv[])
 	if (argc < 2) {
 		cerr << "SCSI Target Emulator RaSCSI Controller" << endl;
 		cerr << "version " << rascsi_get_version_string() << " (" << __DATE__ << ", " << __TIME__ << ")" << endl;
-		cerr << "Usage: " << argv[0] << " -i ID [-u UNIT] [-c CMD] [-t TYPE] [-b BLOCK_SIZE] [-n NAME] [-f FILE] ";
+		cerr << "Usage: " << argv[0] << " -i ID [-u UNIT] [-c CMD] [-t TYPE] [-b BLOCK_SIZE] [-n NAME] [-f FILE|PARAM] ";
 		cerr << "[-d DEFAULT_IMAGE_FOLDER] [-g LOG_LEVEL] [-h HOST] [-p PORT] [-r RESERVED_IDS] [-l] [-v]" << endl;
 		cerr << " where  ID := {0|1|2|3|4|5|6|7}" << endl;
 		cerr << "        UNIT := {0|1}, default setting is 0." << endl;
@@ -549,7 +549,7 @@ int main(int argc, char* argv[])
 		cerr << "        TYPE := {sahd|schd|scrm|sccd|scmo|scbr|scdp} or convenience type {hd|rm|mo|cd|bridge|daynaport}" << endl;
 		cerr << "        BLOCK_SIZE := {256|512|1024|2048|4096) bytes per hard disk drive block" << endl;
 		cerr << "        NAME := name of device to attach (VENDOR:PRODUCT:REVISION)" << endl;
-		cerr << "        FILE := image file path" << endl;
+		cerr << "        FILE|PARAM := image file path or device-specific parameter" << endl;
 		cerr << "        DEFAULT_IMAGE_FOLDER := default location for image files, default is '~/images'" << endl;
 		cerr << "        HOST := rascsi host to connect to, default is 'localhost'" << endl;
 		cerr << "        PORT := rascsi port to connect to, default is 6868" << endl;