### 38.2 Understanding effects of PI markers

Each of the PI marker types listed in Table 38-1 produces a predefined effect when DITA2Go encounters a marker of that type in your document.

Table 38-1 PI marker types with predefined effects

Marker type | Purpose | Effect
ALink | Help-system associative link | Content is the text of an ALink identifier
BorderFormat or BorderType | Format property override | Specifies a border subformat for the element
Branch | Scoping in maps | Names a section of a map as a branch
Break | Presentation | Inserts a line, column, or page break in the output
Cell Attr | Table mark-up for HTML and XML | Content is the value of the HTML <td> tag or <th> tag attribute named by Attr, for the enclosing cell
CellClass | Table mark-up for HTML | Content names the CSS class for a table cell
CellGroup | Table mark-up for HTML | Content specifies the group of a header cell
CellID | Table mark-up for HTML | Overrides generated WAI ID attributes for a cell
CellScope | Table mark-up for HTML | Content specifies the scope of a header cell
CellSpan | Table mark-up for HTML | Assigns the span property to a header cell
Code | Insert HTML or RTF code | Content is used as code; macros are expanded
Config | Change configuration setting for HTML or RTF | Content is a [Section]Key=Value or [Section]=Value setting for HTML or RTF output
ConrefBranch | Map branch processing | Directs a conref to a named map branch
Delete | No standalone purpose | Deletes itself
DITA* | Provide DITA mark-up | See Table 24-2
DocBook* | Provide DocBook mark-up | See Table 26-1
EclipseAnchor | Merge Eclipse Help projects | Marks where a secondary TOC should be inserted
EclipseContext | Context-sensitive help | Content is the context ID for an infopop
EclipseLink | Merge Eclipse Help projects | Content includes path to secondary TOC file
ExtCodeEndChar | Include text from external files | Last character of external file to include
ExtCodeEndLine | Include text from external files | Last line of external file to include
ExtCodeFileEnc | Include text from external files | Encoding of external file
ExtCodeFileLen | Include text from external files | Length of external file in characters
ExtCodeStartChar | Include text from external files | First character of external file to include
ExtCodeStartLine | Include text from external files | First line of external file to include
ExtrBottom | Extract files for HTML | Content is the last item in the <body> of an extract
ExtrDisable | Extract files for HTML | Turns off extract processing
ExtrEnable | Extract files for HTML | Turns on extract processing
ExtrEnd | Extract files for HTML | Ends an extract
ExtrFinish | Extract files for HTML | Marks the last paragraph of an extract
ExtrHead | Extract files for HTML | Content is placed in the <head> of an extract
ExtrReplace | Extract files for HTML | Content replaces an extract in the original file
ExtrStart | Extract files for HTML | Marks the first paragraph of an extract
ExtrTop | Extract files for HTML | Content is the first item in the <body> of an extract
FileName | Split or extract HTML files | Content is the name of a split or extract file
Graph Attr | Image mark-up for HTML and XML | Content is the value of the HTML <img> tag attribute named by Attr for the next image
GraphDpi | Image resolution | Overrides any other DPI setting for the graphic
HelpMerge | Merge Help files | Marks where the named Help file should be inserted
HTMLComment | Add comments to HTML | Content is the text of an HTML comment
HTMConfig | Change configuration setting for HTML | Content is a [Section]Key=Value or [Section]=Value setting for HTML
HyperAlert | Produce a notice | Content is the text of an HTML “alert” notice
HyperAnchor | Provide an anchor for links | Inserts a named <a> tag in HTML
HyperJump | Link to an anchor | Content is the HTML <a href= ...> attribute
HyperLink | Link to an external URI | Content is the HTML <a href= ...> attribute
HyperPopup | Pop up a secondary window | Pops up a temporary window in HTML
HyperTarget | Specify a target window | Specifies the window to use for a link destination
JH2Pop Prop | JavaHelp window property | Content is a JavaHelp 2 pop-up window parameter
JH2Sec Prop | JavaHelp window property | Content is a JavaHelp 2 secondary window parameter
KeyrefBranch | Map branch processing | Names the map branch to use to resolve the next keyref
Link Attr | Link mark-up for HTML and XML | Content is the value of the HTML <a href=...> tag attribute named by Attr, for the next link
LinkClass | Link mark-up for HTML | Content names the CSS class for the next link
LocalTOCTitle | Split files for HTML | Content is the text of a local-TOC link
Meta Type | <meta> tag for HTML | Content is the content value for a new <meta name=Type content=...> tag
Print | Conditional output | Content determines whether current topic is for print output, only for print output, or not for print output
Row Attr | Table mark-up for HTML and XML | Content is the value of the <tr> or <row> attribute named by Attr, for the row of the enclosing cell
RTFConfig | Change configuration setting for RTF | Content is a [Section]Key=Value or [Section]=Value setting for RTF
Search | Conditional output | Content determines whether content is included in FTS
ShadeFormat or ShadeType | Format property override | Specifies a shading subformat for the element
SimpleTableRelCol | Table properties | Specifies relative or absolute column widths for tables
SimpleTableWidth | Table properties | Specifies the absolute width of a table
Split | Split files for HTML | Marks a split point in a DITA file
Table Attr | Table mark-up for HTML and XML | Content is the value of the HTML <table> tag attribute named by Attr, for the enclosing table
Title | Split or extract files for HTML | Content is the page title of a split or extract file
TopicAlias | Context-sensitive help | Inserts a named CSH target in output
TopicStartCode | <head> code for HTML | Code is executed before topic content is processed
Window | HTML Help secondary window | Content names a window for jumps from contents or index
XrefBranch | Map branch processing | Directs a cross reference to a named map branch

You can invent your own custom PI marker types. Any PI marker with a qualifying target (dtrtf, dthtm, or dtall), where DITA2Go does not reserve the attribute name, becomes a valid PI marker. The type is the attribute name, and the content is the attribute value. For example:

    <?dthtm zzTest="My test content" ?>

is a PI marker of type zzTest, and can be mapped in [MarkerTypes], so you could assign it other PI marker type properties:

    [MarkerTypes]
    zzTest = TopicStartCode

When you invent a new custom PI marker type, the name must not conflict with your use of any of the predefined PI marker types listed in Table 38-1.

Avoid adding a custom PI marker type whose name has any of the following characteristics:

- Duplicates the name of a PI marker type listed in Table 38-1, if you intend to use PI markers of that type for the purpose shown.
- Begins with Cell, Char, Graph, Link, Meta, Para, Row, or Table if you are generating HTML or XML, unless you end the name with a valid attribute name. All such PI markers are assumed by DITA2Go to be attribute markers; see §38.3 Adding attributes with PI markers.
- Begins with JH2Pop or JH2Sec if you are generating JavaHelp 2, unless you end the name with a valid JavaHelp 2 window-access object property; see §20.8.1.5 Overriding window-access properties with markers.

Previous Topic: 38.1.3 Deciding when to use PI markers

Next Topic: 38.3 Adding attributes with PI markers

Parent Topic: 38. Working with processing instructions

Sibling Topics:

38.1 Understanding DITA2Go PI markers

38.3 Adding attributes with PI markers

38.4 Assigning properties to PI marker types

38.5 Inserting code with PI markers