V

V ac
Volts alternating current.

validation data
In Cryptographic Support, information about a customer used to create and verify the customer's personal identification number (PIN).

validity checking
(1) To verify the contents of a field.
(2) To verify that object names used in DB2 UDB for AS/400 SQL statements exist on your system.

value
(1) Data (numbers or character strings) entered in any entry field, and data supplied in parameters of CL commands.
(2) In DCE X/Open Object Management (XOM), an arbitrary and complex information item that can be viewed as a characteristic or property of an object. See attribute value.
(3) The smallest unit of data manipulated by the Structured Query Language.
(4) In query management, a quantity assigned to a keyword or variable associated with a query command. If the keyword is part of the command string, its value is separated from it with an equal sign (=). If the keyword is an argument on the extended interface, its value will also be an argument.

value type
In query management, one of the arguments passed to the extended interface. The value type specifies the data type of the value associated with the keyword.

variable
A name used to represent data that can be changed while the program or procedure is running.

variable buffer
A storage area used to pass dialog variables between the application program and the user interface manager (UIM).

variable data
In AFP Utilities, an element in the record layout whose value is represented in the database file. Contrast with fixed data.

variable length
The length of a record or field that can be changed. Contrast with fixed length.

variable-length
Pertaining to a characteristic of a file in which the records can be of varying length, or pertaining to a characteristic of a field on a display that can be of varying length. Contrast with fixed-length.

variable occurrence data item
In COBOL, a table element that is repeated a variable number of times. Such an item must contain an OCCURS DEPENDING ON clause in its data description entry, or be subordinate to such an item.

variable pattern
In REXX, a parsing pattern that uses variables to specify where a string of characters is parsed. The value of the variable can be set by the user and can change while running.

variable pool
In the user interface manager (UIM), the collection of dialog variables defined for an opened application program.

variable pool interface
In REXX, an application program interface that allows programs written in other languages to access variables being used by or contained in an active REXX program.

variable record
The named element of a panel group that identifies the content and layout for the storage area of the dialog variables.

variable symbol
In a REXX exec, a symbol that is assigned a value by the user or in some cases by the REXX/400 interpreter. The value of a variable symbol can be tested and changed using control statements.

variant
For Cryptographic Support, see host master-key variant.

varying array
In DCE Remote Procedure Call (RPC), an array in which part of its contents is transmitted during a remote procedure call.

varying-length string
In DB2 UDB for AS/400, a character string whose length is not fixed, but variable within limits. Contract with fixed-length string.

vary off
To make a device, controller, line, or network interface unavailable for its normal, intended use.

vary on
To make a device, controller, line, or network interface available for its normal, intended use.

VC
See virtual circuit (VC).

V dc
Volts direct current.

VDD
See virtual device driver (VDD).

VDM
See DOS session.

vector
(1) In DCE Remote Procedure Call (RPC), an array of references to other structures.
(2) In the GDDM function, a directed line segment; a straight line between two points.
(3) In SNA, a data structure containing three fields: a length field that specifies the length of the vector in which it is contained, an identifier or type field, and a value field. The value field may contain subvectors.

vector symbol set (VSS)
In the GDDM function, a set of characters each of which is treated as a small picture and is described by a sequence of lines and arcs. Characters in a vector symbol set can be drawn to scale, rotated, and positioned precisely. Contrast with image symbol set (ISS); see also graphics symbol set.

Vendor Independent Messaging (VIM)
An application program interface (API) defined by Apple Computer, Inc.; Borland International, Inc.; Lotus Development Corporation; and Novell, Inc.

Venn diagram
A graphic image consisting of overlapping circles that represent the logical relationship of two sets of information.

verb
A reserved word that expresses an action to be taken by a COBOL compiler or an object program.

version
(1) A separate IBM licensed program, based on an existing IBM licensed program, that usually has significant new code or new function. Each version has its own license, terms, conditions, product type number, monthly charge, documentation, test allowance (if applicable), and programming support category. The numbering of versions starts with Version 2. See also modification level and release.
(2) In the Application Development Manager feature of the Application Development ToolSet licensed program, a separate program or release, new or based on an existing application, that contains significant new code or function.

vertical format information
In TCP/IP, information, such as tab markers, that automatically positions lines of text with respect to other lines of text, according to defined rules. Vertical format information is usually associated with word processing.

Vertical Licensed Internal Code (VLIC)
Programming that defines logical operations on data. The Vertical Licensed Internal Code translates the machine interface (MI) instructions.

vertically displayed records
Subfile records that are grouped so that each record is displayed on one or more lines. Each record begins a new line.

view
(1) The form in which an object is presented. A choice in the action bar that a user selects to look at an object from various perspectives is an example of a view.
(2) A choice in the action bar that a user selects to look at an object from various perspectives.
(3) In DB2 UDB for AS/400, an alternative representation of data from one or more tables. A view can include all or some of the columns contained in the table or tables on which it is defined.

viewport
In the GDDM function, a rectangular area within the picture space that defines where the output of the current page appears on the work station.

VIM
See Vendor Independent Messaging (VIM).

virtual
Pertaining to not physically existing as such but made by software to appear to do so.

virtual address translation
The conversion of virtual storage addresses to real storage addresses.

virtual call
An X.25 user facility in which a call setup procedure and a call clearing procedure determine a period of communications between two DTEs in which the users' data will be transferred in the network in the packet mode of operation. All the users' data is delivered from the network in the same order in which it is received by the network. Synonym for switched virtual call.

virtual circuit (VC)
In a packet-switching data network, a logical end-to-end transmission channel--as opposed to a physical connection--that connects X.25 users. Virtual circuits allow physical transmission facilities to be shared by many users simultaneously. A virtual circuit is a logical connection established between two DTEs. See also permanent virtual circuit (PVC) and switched virtual circuit (SVC).

virtual controller
(1) A controller description that emulates the function of a physical controller for communication with a remote device. As an example, when a PC is attached to the AS/400 system, a virtual controller must be created to allow the PC to communicate with the system.
(2) A controller description that is used by Advanced Peer-to-Peer Networking (APPN) and high-performance routing (HPR) support to attach and manage APPN device descriptions. This type of controller does not represent a connection to a remote station.

virtual device
A device description that does not have hardware associated with it. It is used to form a connection between a user and a physical work station attached to a remote system. A virtual device can be a virtual display station or a virtual printer. See also virtual work station controller.

virtual device driver (VDD)
A form of device driver used by DOS programs running in a virtual DOS machine. The virtual device driver is used to access devices that must be shared with other processes in the OS/2 operating system, such as the display or mouse.

virtual DOS machine (VDM)
See DOS session.

virtual machine (VM)
(1) A system where each user appears to have his own computer and input/output devices.
(2) A functional simulation of a computer and its associated input/output devices.

virtual node
The node associated with a connection network when a route is calculated that goes through that connection network.

virtual party
In telephony, a party that does not actually take part in a telephone call. A virtual party is represented by a special directory number or numbers.

virtual printer
In Client Access, a printer attached to a host system that can receive output from a personal computer for printing. A virtual printer allows a user to use a printer attached to the host system as though the printer were directly attached to a personal computer.

virtual private network (VPN)
An extension of a company's intranet over the existing framework of either a public or private network. A VPN ensures that the data that is sent between the two endpoints of its connection remains secure.

Virtual Storage Access Method (VSAM)
An IBM licensed program that controls communication and the flow of data in an SNA network. It provides single-domain, multiple-domain, and interconnected network capability. VSAM is emulated in CICS to control access to files.

virtual storage (VS)
An addressing scheme that allows external disk storage to appear as main storage.

virtual terminal
In TCP/IP, a system object, created and controlled by an application program, that provides a functional representation or simulation of a physical display station.

virtual terminal manager/function manager (VTM/FM)
The function that provides an application program interface to terminal handling components residing below the machine interface on the AS/400 system.

virtual terminal manager (VTM)
A Vertical Licensed Internal Code component that provides an interface to handle input/output to virtual devices on the AS/400 system.

virtual work station controller
A work station controller description that has the characteristics of a locally attached work station controller but does not exist as hardware. See also virtual device.

virus
A program that can change other programs to include a copy of itself. The other programs are then said to be infected by the virus. Additionally, the virus can perform other operations that can take up system resources or destroy data.

VisualAge for C++
A licensed program that along with VisualAge for C++ for Windows allows for the development of C++ applications for Windows, for OS/400, or for both in a client/server environment.

Visual Explain
In DB2 for AS/400, an interface that graphically displays the access plan of a query.

VisualGen Host Services
A licensed program that includes runtime services support for running generated COBOL applications under OS/400.

vital product data (VPD)
(1) A structured description of a device or program. For devices, it is recorded in the device at manufacture and includes at least the type, model, serial number, and installed features. It may include the manufacturer's ID and other fields. For programs, it is compiled as a data area accompanying the program and includes the name of the licensed program or Licensed Internal Code group, the release and modification, the program module names, the national language or languages selected, and possibly other fields. Vital product data is transferred from the device to the system and stored for display. Vital product data is also visible on the device name plate or a similar tag.
(2) In System Manager, self-defining information stored within the licensed programs, Licensed Internal Code groups, and hardware elements that comprise a system.

VLIC
See Vertical Licensed Internal Code (VLIC).

VLIC log
A list of problem analysis information created by Vertical Licensed Internal Code.

VM
See virtual machine (VM).

VM/MVS bridge
A function of the Communications Utilities licensed program that provides distribution services between an AS/400 SNADS network and both a VM Remote Spooling Communications Subsystem (RSCS) network and a Multiple Virtual Storage/Job Entry Subsystem (MVS/JES) network. Formerly known as RSCS/PROFS bridge. See also bridge, OfficeVision/VM, and Remote Spooling Communications Subsystem (RSCS).

voice-grade telephone line
A telephone line that is normally used for voice communications. The line requires a modem for data communications.

voice response unit (VRU)
In telephony, hardware or software that receives incoming calls by playing one or more prerecorded messages. The messages may require the caller to give additional information by touching buttons on a Touch-Tone keypad. The sequence of messages planned may be determined dynamically by this additional input.

volume
A storage medium that is put on or taken off the system as a unit, for example, magnetic tape or diskette.

volume label
The first 80 bytes on a standard tape used to identify the tape volume and its owner. This area contains VOL1 in the first four positions.

volume statistics
Statistical information about the activity on a tape, diskette, or cartridge volume including statistics about the session (such as the number of read, write, and retry operations), and "lifetime" (accumulated) statistics (such as the number of read and write errors and the number of bytes read and written).

volume table of contents (VTOC)
An area on a disk or diskette that describes the location, size, and other characteristics of each file, library, and folder on the disk or diskette.

vote
In the two-phase commit protocol, the response of an agent to the request of the initiator. The application transaction program uses the responses to determine if it should commit or roll back its protected resources.

voted read-only (VRO)
The voted read-only logical unit of work (LUW) state indicates that the current LUW had no pending changes, was allowed to vote read-only, and did so.

vote read only
The response, to a Prepare presentation services header with a Forget presentation services header, by the agent when no changes have been made to the resources, for the optimization of the two-phase commit flows.

VPD
See vital product data (VPD).

VPN
See virtual private network (VPN).

VRU
See voice response unit (VRU).

VS
See virtual storage (VS).

VSAM
See Virtual Storage Access Method (VSAM).

V-Series Recommendations
A document, CCITT Recommendation V-Series, that outlines standards for the interface between data terminal equipment (DTE) and a synchronous modem.

VSS
See vector symbol set (VSS).

VTM
See virtual terminal manager (VTM).

VTM/FM
See virtual terminal manager/function manager (VTM/FM).

VTOC
See volume table of contents (VTOC).

VT100
A character-mode work station. Characters are sent immediately to the host system when a key is pressed.

VT100 work station protocol
AS/400 support for the VT100 work station protocol allows an AS/400 user to access, using AS/400 TELNET VT100 client support, VT100 application programs on other systems in a TCP/IP network. Users on other systems with a TELNET VT100 client emulation package are able to access AS/400 application programs through the AS/400 TELNET VT100 server.

VT220
A character-mode work station. Characters are sent immediately to the host system when a key is pressed.

VT220 work station
An ASCII full-screen work station manufactured by Digital Equipment Corporation (DEC).

VT220 work station protocol
AS/400 support for the VT220 work station protocol allows an AS/400 user to access, using AS/400 TELNET VT220 client support, VT220 application programs on other systems in a TCP/IP network. Users on other systems with a TELNET VT220 client emulation package are able to access AS/400 application programs through the AS/400 TELNET VT220 server.

VxRxMx
For IBM-supplied licensed programs, the specific level of a program or a temporary fix. VxRxMx includes a version, release, and modification.

V.24
In data communications, a specification of the CCITT that defines the list of definitions for interchange circuits between data terminal equipment (DTE) and data circuit-terminating equipment (DCE).

V.25
In data communications, a specification of the CCITT that defines the automatic answering equipment or parallel automatic calling equipment or both on the General Switched Telephone Network, including procedures for disabling of echo controlled devices for both manually and automatically established calls.

V.25bis
In data communications, an interim specification of the CCITT that defines the connection of data terminal equipment to a serial-dial interface of a public switched telephone network.

V.35
In data communications, a specification of the CCITT that defines the list of definitions for interchange circuits between data terminal equipment (DTE) and data circuit-terminating equipment (DCE) at data rates of 48 kilobits per second.


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