-.BR -l | --lockfile\ < lockfile >
-Prior to accessing serial device specified above the lockfile should be
-acquired for correct concurrent processes behaviour. Although this name
-can be given as direct filename more common method is to use pattern
-with embedded "\fB%s\fP" where this mark is replaced by actual basename
-(last component of pathname with all preceding directory names stripped)
-of serial device used.
-Default name for lockfile is ~\fB DEF_LOCKFILE \fP~.
+.BR -x | --xonxoff
+Turns handshaking mode to \fBXON/XOFF\fP (also called \fBsoftware handshaking\fP).
+Use this mode if you are using only 3-wire serial cable. Device should be
+configured in "\fBAT+IFC=1,1\fP" mode, if \fBAT+IFC\fP command supported. When
+possible, you should rather use \fBRTS/CTS\fP handshaking described in the
+following paragraph. This mode is the default one.
+.TP
+.BR -C | --rtscts
+Turns handshaking mode to \fBRTS/CTS\fP (also called \fBhardware handshaking\fP).
+Use this mode if you are using full 7-wire (approx.) serial cable. Device should be
+configured in "\fBAT+IFC=2,2\fP" mode, if \fBAT+IFC\fP command supported. Try
+to use this mode whenever possible (instead of the default \fBXON/XOFF\fP mode described
+in the previous paragraph). This mode may not be available in your UNIX flavour.
+.TP
+.BR -M | --smsmode
+Forces the SMS mode to use - either \fBpdu\fP or \fB text\fP mode. By default
+.B mdsms
+tries to detect mode to use automatically, \fBPDU\fP mode is preferred. When
+your modem is capable of both modes and you need for some reasone \fBtext\fP
+mode, you may use \fB--smsmode text\fP argument to force it. \fBPDU\fP mode
+is recommended for unattended operation, on the other side \fBtext\fP mode
+should be more compatible when you have compatibility problems with unsupported
+GSM modem. It is recommended to force the exact mode you will be using in
+unattanded operaton. By such way you will prevent failures caused by the other
+mode after possible random communication glitches (and therefore automatic
+.B mdsms
+switchover).
+.TP
+.BR -P | --pdusmscmode
+Forces SMS center prepending mode for \fBPDU mode\fP operation. By default
+.B mdsms
+tries sequentially all the described modes, you should lock it for
+unattanded operation to prevent vain switchovers from random communication
+glitches (also you will notice faster response for "\fBcount-out\fP" or
+"\fBnone\fP" modes):
+.RS
+.TP
+.BR count-in
+The default mode, SMS center is prepended to the \fBPDU\fP and SMS
+.RB "center's"
+length is taken into account during length calculation for "\fBAT+CMGS=\fP#".
+.TP
+.BR count-out
+SMS center is prepended to the \fBPDU\fP but SMS
+.RB "center's"
+length is omitted
+during length calculation for "\fBAT+CMGS=\fP#".
+.TP
+.BR none
+SMS center is \fBNOT\fP prepended to the \fBPDU\fP, SMS center to use by
+GSM modem is taken from the one set by
+\fBAT+CSCA="\fPsmsc # from user\fB"\fP
+command.
+.RE