Common Desktop Environment: Help System Author's and Programmer's Guide


application help

Online help for a particular application (software).

application-defined link

A hyperlink designed especially for invoking some application behavior. To invoke the behavior, the help must be displayed in dialogs created by the application. (Application-defined hyperlinks are ignored by Helpview.)

automatic help

Help presented by the system as the result of a particular condition or error. Sometimes called "system initiated" help. For example, error dialogs are a form of "automatic help." See also semi-automatic help and manual help.

browser volume

The desktop uses the Helpview program as a "help browser" by displaying a special browser volume that lists the help installed on the system. A utility called dthelpgen creates this volume in the user's home directory.


A warning to the user about possible loss of data. See also note and warning.

close callback

An application function called when a help dialog box is closed.

context-sensitive help

Online information that is relevant to what the user is doing within an application. Sometimes, pressing the F1 key is referred to as "context-sensitive help" because the choice of help topic is based on the user's context.

cross-volume hyperlink

A hyperlink that jumps to a topic in a different help volume. Cross-volume hyperlinks are entered using the <link> element, where the hyperlink parameter specifies the volume name and an ID (separated by a space):

<link hyperlink="volume">text<\link> 
dialog cache

A list of help dialogs that has been created but may not be in use. When the application needs a new help dialog, it first searches its dialog cache for an unused dialog. If one is found, it is used. Otherwise, all dialogs are in use, so a new one is created.

Document Type Definition

A description of a set of elements used to create a structured (or hierarchical) information. The Document Type Definition (DTD) specifies the syntax for each element and governs how and where elements can be used in a document.


A logical portion of information, such as a book title, a paragraph, a list, or a topic. Normally, the extent of an element is marked by tags, although the tags for some elements are assumed by context.


An element of text that calls attention to the text (usually by being formatted as italic).


A text string or file with a name. Most entities are named by the author (using the <!entity> element), but some entities are predefined. See also entity declaration and entity reference.

entity declaration

Markup that establishes an entity name and its value. See also entity and entity reference.

entity reference

Use of an entity name preceded by an & (ampersand) and followed by a ; (semicolon) that indicates to HelpTag that the entity is to be inserted where the entity name appears. See also entity and entity declaration.

entry point

A point within a help volume that may be displayed directly as the result of a request for help. That is, a topic where the user may " "enter" or begin reading online help. Any topic, or location within a topic, that has an ID can become an entry point.

example listing

A body of text in which line breaks are left as they are and which is displayed in a computer font. The text is typically an example of a portion of a computer file. Example listings are entered using the <ex> or <vex> elements.

execution alias

A resource that assigns a name to a command string or script that an execution link executes.

execution link

A hyperlink that executes a shell command or script.

execution policy

The Help System provides a resource that can be set to control the behavior of execution links. This enables a system administrator or user to establish an appropriate level of security for any given application.


A graphic or illustration that appears in the help information.

formal markup

A tag set and accompanying usage rules that are specified in the Helptag 1.3 Document Type Defnition (DTD). By following the rules set forth in the DTD, an author can produce Standard Generalized Markup Language (SGML) compliant help source files.

general help dialog box

A window in which help information is displayed. General help dialog boxes have a menu bar, a topic tree (which provides a list of topics), and a help topic display area. See also quick help dialogbox.

help callback

An application function called when the user presses the F1 key.

help family

A set of help volumes that are related to one another because the applications they refer to are related.

help key

A designated key, usually the F1 function key, used to request help on the current context. Some keyboards have a dedicated Help key that may take the place of F1. In OSF/Motif applications, the help key is enabled by adding a help callback to a widget.

help on help

Help information about how to use the help dialog boxes. The user gets this information by pressing F1 while using a help window, or by choosing Using Help from the Help menu in a general help dialog box.

help volume

A complete body of information about a subject. Also, this term can refer to either the set of source files that contain the marked-up text or the run-time files generated by running HelpTag.

History dialog box

A dialog box that shows a list of the sequence of topics the user has visited. The history sequence can be traversed in reverse order to make it easy for the user to return to earlier topics.

home topic

The topic at the top of the hierarchy in a help volume. This is the topic that is displayed when the user indicates a desire to browse a help volume. HelpTag provides a built-in ID for the home topic: _hometopic.


A segment of text (word or phrase) or graphic image that has some behavior associated with it. The most common type of hyperlink is a "jump" link, which connects to a related topic. When the user chooses a jump link, the related topic is displayed. Hyperlinks can also be used to invoke other kinds of behavior, such as executing a system command or invoking specific application behavior.

hyperlink callback

An application function that is invoked when a user chooses a hyperlink. This function is responsible for handling the types of hyperlinks not handled automatically within the help dialog.


A list of important words and phrases that appear throughout a help volume. The index is an alphabetical list of the words or phrases that can be searched to find help on a subject. The Help System displays the index when the user chooses the Index button (in a general help dialog box). See also Index Search dialog box.

Index Search dialog box

A dialog box that shows a list of index entries for a help volume. An index can be displayed for the current volume, selected volumes, or all help volumes. A user can search the index for a word or phrase and any corresponding topics that contain the search string will be listed.

inline graphic

A small graphic (illustration) that appears within a line of text.

jump-new-view hyperlink

A hyperlink that, when chosen, displays its information in a new dialog box. Jump-new-view links are intended for cross-volume links. The user senses a "new context" by a new window being displayed.

man page link

A hyperlink that, if activated, displays a "man page," which is a brief online explanation of a system command. The information in man pages are not supplied through the HelpTag system.

manual help

A style of online help that requires the user to know what help is needed and how to get it. For example, most commands in a Help menu are considered "manual" help because the user chooses when and what to view. See also automatic help and semi-automatic help.


A message to the user that draws attention to important information. If the information is critically important, a caution or warning is used instead. See also caution and warning.


The portion of the HelpTag software that reads the source files (which are created by the author) and converts them into run-time help files that the Help System dialogs can read. If the author uses markup incorrectly (or incompletely), the parser detects the problems and indicates that "parser errors" have occurred.

quick help dialog box

A streamlined help dialog box that has a help topic display area and one or more push buttons. See also general help dialog box, which offers additional capabilities.


The process of declaring a help volume to be accessible for browsing or cross-volume linking.

run-time help files

The files generated by the dthelptag command. These are the files distributed to users who will use the Help System.

Search Volume Selection dialog box

A dialog box that lists the help volumes available on a user's system. When a user chooses Selected from the Index Search dialog box, this dialog box lists help volumes that the user can select. One or more volume names can be selected and the corresponding index information is reported in the Index Search dialog box.

semi-automatic help

A style of online help in which the user requests help and the system decides, based on the current circumstances, which help information to display. "Context-sensitive" help (pressing the F1 key) is an example of semi-automatic help. See also automatic help and manual help.

short form markup

An abbreviated way of marking an element where the end tag is marked with a single vertical bar and the last character of the begin tag is also a vertical bar. For example, the short form of the <book> element is:

shorthand markup

An abbreviated way of marking an element where the start and end tags are replaced with a special two-character sequence. For example, the shorthand form of the <computer> element is two opening single quotation marks followed by two closing single quotation marks like this:

standalone help

Help information intended to be used independently of application software. For example, online help that explains the basics of computer programming may not be associated with a particular application. A standalone help volume can be displayed using the dthelpview command.

Standard Generalized Markup Language (SGML)

An international standard [ISO 8879: 1986] that establishes a method for information interchange. SGML prescribes constructs for marking the structure of information separate from its intended presentation or format. The HelpTag markup language conforms to this SGML standard.


A text string that marks the beginning or end of an element. A start tag consists of a < (left angle bracket) followed by a special character string (consisting of only letters), optional parameters and values, and terminated by a > (right angle bracket).

An end tag consists of a < (left angle bracket), a \ (backslash), the same special character string, and a > (right angle bracket). Formal markup uses a / (forward slash) in the end tag syntax.

Tagged Image File Format (TIFF)

A standard graphics file format. The Help System dialog boxes support TIFF 5.0 images. TIFF images are identified by the .tif file-name extension.


Information about a specific subject. Usually, this is approximately one screenful of information. Online help topics are linked to one another through hyperlinks.

topic hierarchy

A help volume's branching structure in which the home topic branches out (through hyperlinks) to progressively more detailed topics. See also home topic.

topic tree

In a general help dialog box, a list of topics that can be selected to display help information.


Information that warns the user about possible injury or unrecoverable loss of data. See also caution and note.


The fundamental building block of graphical user interfaces. The OSF/Motif widget set provides widgets of all sorts, suitable for constructing an application user interface.

X bitmap

A two-tone image that has one foreground color and one background color. Bitmap image files are identified by file-name extension.

X pixmap

A multicolor image. Pixmap image files are identified by file-name extension.

X window dump

An image captured from an X Window System display. The xwd utility is used to capture a window image. X window dump image files are identified by the .xwd file-name extension.