NETDATA

Authorization

General User

Purpose

Use the NETDATA command from within an exec to query, receive, or send files, notes, or acknowledgements in the NETDATA format. Although it is not recommended and is certainly more complex, you may also use NETDATA from the command line.

The NETDATA command is invoked when you issue the NOTE, PEEK, RECEIVE, and SENDFILE commands, or when you issue the DISCARD subcommand from your reader.

Operands

QUERY

requests information about the current reader spool file, if that file is in NETDATA format.

RECEIVE fn ft fm

requests the current reader spool file be processed, if that file is in NETDATA format. The fn ft fm specifies the file identifier to be given to the incoming file. An equal sign (=) can be used for any part of the file identifier to indicate the file name, file type, or file mode is to be the same as that of the file in the spool file.

SEND fn ft fm

requests a note or a file be transmitted to a user ID at a network node in NETDATA format. The fn ft fm specifies the file identifier of the file to be sent. An asterisk (*) can be used for the file mode to indicate all accessed disks or directories be searched for the file.

TO userid

specifies the user on your system or another system to whom the file is to be sent.

Note: This operand must be a user ID, not a nickname in your userid NAMES file.

AT node

specifies the node to which the file is to be sent.

Note: This operand cannot be omitted, even if the user to whom the file is to be sent is on the same system as you are.

Options

Duplicate and conflicting options are allowed and do not result in diagnostic messages. The rightmost option overrides any conflicting options previously entered.

Option A

TYPe

specifies responses will be displayed to the terminal. The TYPE option overrides the FIFO, LIFO, NOTYPE, and STACK options. This is the default.

NOType

specifies responses (excepting prompting messages) will not be displayed to the terminal. The NOTYPE option overrides the FIFO, LIFO, STACK, and TYPE options.

STACK FIFO

STACK LIFO

specifies messages, whether informational or error, are to be placed in the stack in the order in which they would have been typed. The STACK and STACK FIFO option override the LIFO and TYPE options and force the NOTYPE option.

Note:

1. STACK, STACK FIFO, and FIFO are synonymous.
2. STACK LIFO, and LIFO are synonymous.

LIFO

specifies messages, whether informational or error, are placed in the stack in the inverse order in which they are typed (last in, first out). The LIFO option overrides the FIFO, STACK, and TYPE options and forces the NOTYPE option.

FIFO

specifies messages, whether informational or error, are placed in the stack in the order in which they are typed (first in, first out). The FIFO option overrides the LIFO and TYPE options and forces the NOTYPE option.

MSGSubs

returns only the available substitution information for the current spool file. Substitution data in a message is the variable information contained in the message. For more information on substitution data, see Usage Notes.

The lines are displayed or stacked in accordance with the NOTYPE, STACK, LIFO, or FIFO options.

MSGAll

returns the normal message and all available substitution information for the current spool file. The lines are displayed or stacked in accordance with the NOTYPE, STACK, LIFO, and FIFO options described above.

VMDate

displays the dates in the format specified by the user's default date format setting. This is the default. For more information on the user's default date format setting, see Usage Note 3.

SHOrtdate

displays the dates in mm/dd/yy format.

Where:

mm

specifies the month

dd

specifies the day of the month

yy

specifies the 2-digit year

FULLDate

displays the dates in mm/dd/yyyy format.

Where:

mm

specifies the month

dd

specifies the day of the month

yyyy

specifies the 4-digit year

ISOdate

displays the dates in yyyy-mm-dd format.

Where:

yyyy

specifies the 4-digit year

mm

specifies the month

dd

specifies the day of the month

Option B

Fullprompt

specifies a prompt is to be issued for the incoming file. The FULLPROMPT option overrides the MINPROMPT, NOPROMPT, NOSPOOL, and XEDIT options.

Minprompt

specifies a prompt is to be issued for the incoming file whenever its name is different from that of the spool file. The MINPROMPT option overrides the FULLPROMPT, NOPROMPT, NOSPOOL, and XEDIT options. This is the default.

NOPrompt

specifies no prompt is to be issued for the incoming file. The NOPROMPT option overrides the FULLPROMPT and MINPROMPT options.

NEwdate

specifies the date and time recorded for the incoming file is that when it was received. The NEWDATE option overrides the OLDDATE option.

Olddate

specifies the date and time recorded for the incoming file is the date when it was created or last updated by the sender. The OLDDATE option overrides the NEWDATE option. This is the default.

Replace

specifies an existing file is to be replaced by the incoming file. The REPLACE option overrides the NOREPLACE option.

NOReplace

specifies an existing file is not to be replaced by the incoming file. The NOREPLACE option overrides the REPLACE option. This is the default.

NOTE

specifies the file is to be sent or received as a note.

NOTEBook fn

specifies the name of the NOTEBOOK file to which the note being received is to be appended, following a line of 73 equal signs (=). This option is ignored if the file being received is not a note or if the NOTE option was not specified.

PURGE

specifies the file being received is to be purged, not received.

Option C

Ack

specifies an acknowledgement is to be returned to your reader when the recipient receives or discards the file. The ACK option overrides the NOACK option.

NOAck

specifies no acknowledgement is to be returned to you when the recipient receives or discards the file. The NOACK option overrides the ACK option. This is the default.

NOTE

specifies the file is to be sent or received as a note.

CLass c

specifies the spool class to be used when sending the file. The spool class is a 1-character alphanumeric field whose values can be A through Z, 0 through 9, or equal sign (=). If you specify an equal sign (=), the current PUNCH spool class is used when sending the file. The CLASS option is ignored if the NOSPOOL option was specified. The default is Class A.

Option D

Log

specifies the SEND or RECEIVE operation is to be logged in your userid NETLOG file. The LOG option is forced when receiving an acknowledgement. The LOG option overrides the NOLOG option.

NOLog

specifies the SEND or RECEIVE operation is not to be logged in your userid NETLOG file. The NOLOG option is forced when purging an acknowledgement and overrides the LOG option. This is the default.

NOSpool

specifies the status of the punch is not altered during a SEND operation. NOSPOOL also specifies the status of the reader is not altered during a RECEIVE operation. During processing, no CP TAG or CP SPOOL commands are issued. Acknowledgement files will be sent during RECEIVE operations and the punch will be saved, spooled, and tagged, and then restored to send the acknowledgement file. The NOSPOOL operation overrides the FULLPROMPT and MINPROMPT options and forces the NOPROMPT option. The NOSPOOL option also causes the CLASS option to be ignored during SEND operations.

Xedit

specifies the file being sent should be written from XEDIT storage instead of from a minidisk or directory or the file being received should be read into XEDIT storage instead of to a minidisk or directory. Files read into XEDIT storage will also remain in your reader. The XEDIT option overrides the FULLPROMPT and MINPROMPT options and forces the NOPROMPT option. The new text is the underlined text between the two sets of quoted text which is text that exists today.

When sending a file using the XEDIT option, the contents of the file sent will be from the current line pointer to the end of file, the current date and time at the moment the file is sent will be used as the date the file was last updated. This is the date and time which will be recorded for the file if it is received with the OLDDATE option.

Usage Notes

1. The format of the data transmitted and received by the NETDATA command is described in z/VM: CMS Macros and Functions Reference.
2. These messages will be suppressed by the NOTYPE option:
   • NETDATA RECEIVE: responses such as:

     Note fn ft added to fn NOTEBOOK fm

   • NETDATA SEND: responses such as:

     Note fn ft fm sent to userid at node on date time timezone

   • NETDATA QUERY: would suppress all responses.
3. The default date format used for certain CP and CMS commands can be set on a system-wide basis and also for the individual user. The system-wide default date format is set with the SYSTEM_DATEFORMAT system configuration statement. The user's default date format is set with the DATEFORMAT user directory control statement.
   The system-wide default and the user's default can also be set with the CP SET DATEFORMAT command. If SET DATEFORMAT is not specified for an individual user and there is no DATEFORMAT statement in the user's directory entry, the default format for that user is the system-wide default. The system-wide and user settings can be queried with the CP QUERY DATEFORMAT command. The hierarchy of possible date format settings for the NETDATA command, from highest priority to lowest, is the:

   • NETDATA command option
   • DEFAULTS command setting or default
   • User default
   • System-wide default
4. Tailoring the NETDATA Command Options

   You can use the DEFAULTS command to set up options that override the defaults for the NETDATA RECEIVE and NETDATA SEND commands. However, these customized defaults will be overridden by any options typed in from the command line. For more information, see DEFAULTS.

5. MSGSUBS and MSGALL Options

   The substitution data in a message is the variable information it contains. For example, fn ft fm.

   1. The substitution data line generated by the MSGSUBS and MSGALL options contains the message identifier of the actual message, followed by any substitution data. Substitution data is returned only on zero return codes.
   2. If NETDATA is issued with the MSGSUBS or MSGALL option and the TYPE, NOTYPE, STACK, FIFO, or LIFO options are not specified, the result is returned to the terminal.
   3. If MSGSUBS is specified, only the message identifier and the available substitution data is returned. The message itself is not stacked or returned to the terminal.
   4. If MSGALL is specified, both the actual message and the message identifier with the available substitution data are returned. The actual message is the first line returned, and the substitution data is the second line returned.
6. NETDATA SEND

   Acknowledgements

   Users on different computer systems connected by the RSCS network can request an acknowledgement be returned to them when they send a file, to inform them of its status.

   The sender can specify on the NETDATA SEND command an acknowledgement be returned when a file is received. This acknowledgement indicates whether the file was received (written to a disk or directory) or discarded (purged).

   When you receive an acknowledgement that appears in your reader, all parameters and options (except the spoolid and the PURGE option) are ignored. The acknowledgement makes an entry in your userid NETLOG file that confirms the file you sent was received (or discarded). The format of entries in the userid NETLOG file is shown in the Examples.

7. Priority

   When the NETDATA SEND command sends a note or a file across the network (to a node different from yours), the file is assigned a priority. The order and speed of transmission are based on both this priority and the size of the file.

8. The default for NETDATA SEND is to send files as CLASS A NOCONT NOHOLD, regardless of the class to which you spool your PUNCH. If you want NETDATA SEND to use the current PUNCH spool class, specify the CLASS = option on the NETDATA SEND command. The CP message generated, containing the spoolid, and so forth, is suppressed.
9. NETDATA RECEIVE

   The NETDATA RECEIVE command resets the continuous spooling option and spools your reader NOCONT unless the NOSPOOL option is specified.

   Prompting Messages

   FULLPROMPT, MINPROMPT, or NOPROMPT?:

   • If you do not issue either a QUERY RDR command or a RDRLIST command, specify FULLPROMPT.
   • If you do issue a QUERY RDR command before issuing the NETDATA RECEIVE command, specify MINPROMPT.
   • If you issue the NETDATA RECEIVE command from a controlled environment (such as RDRLIST) where the identities of all incoming files are known, specify NOPROMPT.
   If you specify the FULLPROMPT or MINPROMPT option on a NETDATA RECEIVE command, the valid responses include one of the:

   • Digits specified in the prompt
   • Parenthetical words that follows a digit or any initial truncation of the word.
   The meanings of these responses are:

   Response

   Description

   0 or No

   If this file is one of a set of files that constitutes a single spool file, the file is not received and prompting continues for the next file, if there is one. If this is the last file of a set of files or if this is the only file in the spool file, the command is ended.

   1 or Yes

   Receives the file under the name fn1 ft1 fm1 (or fn3 ft3 fm3). For more information on fn1 ft1 fm1 and fn3 ft3 fm3, see Responses.

   2 or Quit

   Ends the command.

   3 or Rename

   Requests prompt message DMS1080R so the incoming file can be received using a different name.

   If you receive prompt message DMS1081R, the valid responses include one of the:

   • Digits specified in the prompt
   • Parenthetical words that follows a digit or any initial truncation of the word.
   The meanings of these responses are:

   Response

   Description

   0 or No

   Does not receive the file under the name fn fn fm and repeats the original prompt message DMS1079R. This allows you to specify a different name for the incoming file.

   1 or Yes

   Receives the file under the name fn ft fm.

   2 or Quit

   Ends the command.

   Note: You cannot receive a note into a packed notebook. Before using NETDATA RECEIVE to receive the note in the reader, use COPYFILE with the UNPACK option to change the file format from packed to unpacked.
10. Special NETDATA Files from MVS™ with TSO Extensions (PP)

    The MVS with TSO Extensions licensed program can send an empty file, in which case NETDATA RECEIVE will give you an error message indicating no file was created. It can also send, as a unique case of multiple files in one transmission, one note and a data file together. The note will be the first file in the transmission and the data file will be second. NETDATA RECEIVE will add the note to the appropriate notebook, receive the data file, and give informative messages for each action. This is the only form of multiple NETDATA files supported by the NETDATA RECEIVE command.

    Note: NETDATA RECEIVE will not handle partitioned data sets or data sets that have been encrypted by Access Method Services (AMS). These files will not be received and remain in the reader. Multiple NETDATA transmissions that do not have a note as the first file result in the first file being received and the other file(s) ignored. The entire spool file is left in the user's reader.
11. Receiving NETDATA Files Using the OLDDATE Option

    If a file is sent in NETDATA format from one location to another in a different time zone and it is received using the OLDDATE option of the NETDATA RECEIVE command, the date and time of the file reflect when it was last modified relative to UTC (Coordinated Universal Time).

    For example, suppose a file was last modified on 1 January 1998 at 14:00 in a time zone that is eight hours west of UTC and it is sent to a time zone five hours west of UTC. When the file is received, the time and date are changed to 1 January 1998 at 17:00.

12. Empty Files
    If you try to use NETDATA RECEIVE to receive an empty file into a minidisk, you will get this message:

    File fileid is empty; minidisk does not support empty files

    The file is not purged from your reader. You can DISCARD or PURGE the file from your reader or you can try to receive it into an SFS directory. If you receive the file into an SFS directory, the file record length, record format and file ID will be transferred to the new file.

Responses

1. If you specify the FULLPROMPT or MINPROMPT option, one of these prompts is displayed:

   DMS1079R  Receive fn1 ft1 fm1?
               Reply 0 (NO), 1 (YES), 2 (QUIT), or 3 (RENAME)
    
               Receive fn1 ft1 fm1 and replace the existing file
               of the same name?
               Reply 0 (NO), 1 (YES), 2 (QUIT), or 3 (RENAME)
    
               Receive fn1 ft1 fm1 and replace fn2 ft2 fm2?
               Reply 0 (NO), 1 (YES), 2 (QUIT), or 3 (RENAME)
    
               Receive fn1 ft1 fm1 as fn3 ft3 fm3?
               Reply 0 (NO), 1 (YES), 2 (QUIT), or 3 (RENAME)
    
               Receive fn1 ft1 fm1 as fn3 ft3 fm3 and replace
               the existing file of the same name?
               Reply 0 (NO), 1 (YES), 2 (QUIT), or 3 (RENAME)
    
               Receive fn1 ft1 fm1 as fn3 ft3 fm3
               and replace fn2 ft2 fm2?
               Reply 0 (NO), 1 (YES), 2 (QUIT), or 3 (RENAME)

   • The file ID fn1 ft1 fm1 is the name from the NETDATA records in the spool file.
   • The phrase and replace the existing file of the same name appears when the operation replaces an existing file and the file mode of that file is the same as fm1.
   • The phrase and replace fn2 ft2 fm2 appears when the operation replaces an existing file and the file mode of that file is not fm1.
   • The file ID fn3 ft3 fm3 is the name you have specified in response to prompting message DMSDDL1080R.
2. If you respond with a 3 (or RENAME) to prompting message DMS1079R, you will receive the prompting message

   DMS1080R  Enter the new name for fn ft fm

   and you must enter a file ID of the form fn [ft [fm]].
3. If you respond to prompting message DMS1080R with a file ID that names an existing file, you will receive the prompting message

   DMS1081R  Replace fn ft fm?
               Reply 0 (NO), 1 (YES), or 2 (QUIT)

4. Successfully receiving a spool file will cause one of these responses to be issued:
   • If the incoming file (fn1 ft1 fm1) does not already exist:

     File fn2 ft2 fm2 created from fn1 ft1 fm1 received
     from userid at node

   • If the incoming file (fn1 ft1 fm1) replaces an existing file (fn2 ft2 fm2):

     File fn2 ft2 fm2 replaced by fn1
     ft1 fm1 received
     from userid at node

   • If the incoming file (fn1 ft1 fm1) replaces an existing file (fn2 ft2 fm2), but is given a mode (fm3) that differs from the mode of the existing file (fm2):

     File fn3 ft3 fm3 replaced fn2 ft2 fm2 with
     fn1 ft1 fm1 received from userid at node

5. Other responses include:
   • File fn ft has been discarded
   • Note fn ft has been discarded
   • Note fn ft added to fn NOTEBOOK fm
   • Ackn date time added to userid NETLOG
   • Ackn date time has been discarded
6. If you specify the MSGSUBS or MSGALL option, the NETDATA command uses this response format when returning the substitution data. This response has a fixed format and fixed length. The length, including blank delimiters and the ending blank, is 184 characters when a date is in the SHORTDATE format. The length, including blank delimiters and the ending blank, is 188 characters when a date is in the FULLDATE or ISODATE format.
   Note:

   1. Each individual field in the substitution line is initialized to an * followed by enough blanks to fill the field, except the LRECL field which is numeric and initialized to zero.
   2. Initialization to the full length of the variables is done to satisfy assembler programmers who call NETDATA and require the full length of each field to avoid parsing.
   The format is (each field is delimited by one blank):

   msgid fileid noteid userid nodeid logdate1 logtime1 logdate2
             logtime2 lrecl overlay sentname

   Where:

   msgid

   consists of a 4-digit message number concatenated with a 2-digit format number. It is the actual message number of the message issued at the completion of the NETDATA command and has a length of six.

   fileid

   consists of three fields, each delimited by one blank: file name (fn), length of eight; file type (ft), length of eight; and file mode (fm), length of two.

   • NETDATA RECEIVE or NETDATA QUERY of a file specifies the fn, ft, and fm that the file will be received as.
   • NETDATA RECEIVE or NETDATA QUERY of a note specifies the fn, ft, and fm that will contain the note.
   • NETDATA RECEIVE or NETDATA QUERY of an acknowledgement specifies the fn, ft, and fm of the netlog that will contain the acknowledgement.
   • NETDATA SEND of a file or note specifies the fn, ft, and fm of the file or note being sent.

   noteid

   consists of three fields, each delimited by one blank: file name (fn), length of eight; file type (ft), length of eight; and file mode (fm), length of two.

   • NETDATA RECEIVE or NETDATA QUERY of a note specifies the fn, ft, and fm of the note sent to you.
   • NETDATA RECEIVE or NETDATA QUERY of a file or an acknowledgement will not set the noteid; therefore, it specifies the initialized value of * in each of the three fields.
   • NETDATA SEND of a file or a note will not set the noteid; therefore, it specifies the initialized value of * in each of the three fields.

   userid

   specifies a user ID, length of eight, for these commands:

   • NETDATA RECEIVE or NETDATA QUERY of a file, a note, or an acknowledgement specifies the user ID of the user who sent the file, note, or acknowledgement.
   • NETDATA SEND of a file or a note specifies the user ID you are sending the file to.

   nodeid

   specifies a node ID, length of eight, for these commands:

   • NETDATA RECEIVE or NETDATA QUERY of a file, a note or an acknowledgement specifies the node ID of the user who sent the file, note, or acknowledgement.
   • NETDATA SEND of a FILE or a NOTE specifies the node ID you are sending the file to.

   logdate1

   specifies the date, length of eight when the date format is SHORTDATE or ten when the date format is FULLDATE or ISODATE when you issue these commands:

   • NETDATA RECEIVE, NETDATA QUERY, or NETDATA SEND for a file or note.
   • NETDATA RECEIVE, NETDATA QUERY, or NETDATA SEND for an acknowledgement is the date the original file or note was sent.

   logtime1

   specifies the time, length of eight, when you issue these commands:

   • NETDATA RECEIVE, NETDATA QUERY, or NETDATA SEND for a file or note.
   • NETDATA RECEIVE, NETDATA QUERY, or NETDATA SEND for an acknowledgement is the time the original file or note was sent.

   logdate2

   specifies the date, length of eight when the date format is SHORTDATE or ten when the date format is FULLDATE or ISODATE when you issue these commands:

   • NETDATA RECEIVE or NETDATA QUERY for an acknowledgement.
   • NETDATA RECEIVE, NETDATA QUERY, or NETDATA SEND for a file or a note will not set the date; therefore, it specifies the initialized value of *.

   logtime2

   specifies the time, length of eight, when you issue these commands:

   • NETDATA RECEIVE or NETDATA QUERY for an acknowledgement
   • NETDATA RECEIVE, NETDATA QUERY, or NETDATA SEND for a file or a note will not set the time; therefore, it specifies the initialized value of *.

   lrecl

   specifies the logical record length, length of 14, for these commands:

   • NETDATA RECEIVE or NETDATA QUERY of a file or a note.
   • NETDATA SEND of a FILE or a NOTE will not set the logical record length; therefore, it specifies the initialized value of zero.
   • NETDATA RECEIVE or NETDATA QUERY of an acknowledgement will not set the logical record length; therefore, it specifies the initialized value of zero.

   overlay

   consists of three fields, each delimited by one blank: file name (fn), length of eight; file type (ft), length of eight; and file mode (fm), length of two.

   • NETDATA RECEIVE specifies the fn, ft, and fm of the file you are replacing. If the REPLACE option is not specified, this field is initialized to a value of * in each of the three fields.
     Note: It is used when the file you are replacing has the same fn and ft, but has a different fm.

     Example

     If TEST FILE A1 exists and you issue this command:

     NETDATA RECEIVE TEST FILE A2 (MSGALL REPLACE

     overlay will be TEST FILE A1.
   • NETDATA QUERY or NETDATA SEND is not set for this field; therefore, it specifies the initialized value of * in each of the three fields.

   sentname

   specifies the name of a file for:

   • NETDATA RECEIVE or NETDATA SEND specifies the name of the file as specified by the sender. The value in this field is dependent on the origin of the file. If the file originated on a CMS system it is in the form fn ft fm. If it originated on the MVS system, it is in the standard MVS file format (xxxxxx.xxxx.xxxxx___ up to 44 characters in length).
   • NETDATA SEND is not set for this field; therefore, it specifies the initialized value of *.

7. NETDATA QUERY Output

   These examples use the same format variables as Usage Note 6.

   Note: All the dates are displayed in the SHORTDATE date format because the user's virtual machine setting is set to SHORTDATE.
   • NETDATA QUERY output for an acknowledgment file has this format:

     Ackn logdate2 logtime2 recv|disc by userid at nodeid on logdate1 logtime1

     For example:

     Ackn 07/10/98 07:48:20 disc by SMITHRM at GDLVMA on 07/10/92 07:45:33

   • NETDATA QUERY output for a file has this format:

     File LRECL lrecl recv from userid at nodeid on logdate1
        logtime1 sent as sentname

     For example:

     File LRECL 63 recv from SMITHRM at GDLVMA on 07/10/98 07:45:33
     sent as SAMPLE EXEC B1

   • NETDATA QUERY output for a note has this format:

     Note LRECL lrecl recv from userid at nodeid on logdate1 logtime1

     For example:

     Note LRECL 132 recv from SMITHRM at GDLVMA on 07/10/98 07:45:33

Messages and Return Codes

• DMS006E No read/write filemode accessed for fn ft [RC=36]
• DMS024E File fn ft fm already exists; specify REPLACE option [RC=28]
• DMS037E Filemode mode accessed as read/only [RC=12|36]
• DMS062E Invalid character char in fileid fn ft [RC=20]
• DMS069E Filemode mode not accessed [RC=36]
• DMS078E Invalid card in reader deck [RC=32]
• DMS109S Virtual storage capacity exceeded [RC=104]
• DMS205W Reader empty, reader not ready or empty reader file [RC=100]
• DMS257T Internal system error at address hex (offset hex)
• DMS636E Unsupported type of NETDATA file [RC=88]
• DMS636W File fileid is empty; minidisk|filepool filepoolid does not support empty files [RC=74|88]
• DMS638E entry type is too wide to append to fn ft [RC=32]
• DMS639E Error in name routine; return code was nnnnnnnn [RC=100]
• DMS688E XEDIT option only valid from XEDIT environment [RC=24]
• DMS743E File fn ft fm is in an invalid format [RC=40]
• DMS1123E Unknown response text ignored
• DMS1124W Spool file spoolid has been left in your reader because one or more files were not received [RC=1]
• DMS1138E Filesharing conflict involving file fn ft fm [RC=31│55│99│100]
• DMS1184E File fn ft fm not found or you are not authorized for it [RC=28]
• DMS1262S Error nnn closing │ opening file fn ft fm [RC=25│28│30│31│37│40│55│70│ 80│81│82│83│84│99]
• DMS1285S Default option option is invalid [RC=24]
• DMS514E Return code nn from NETDATA [RC=24]

Additional system messages may be issued by this command. The reasons for these messages and their location are: