Glossary

Table of Contents

Glossary

Glossary

alignment

The horizontal placement of text in a paragraph. The four available alignments are: left, right, center and justify. TopLeaf provides two additional alignments (inside and outside) for fixed blocks only.

ancestor

In the XML hierarchy, any element which contains the current element.

API

Application Programming Interface. A mechanism by which third party applications can access many of the functions of the TopLeaf typesetting system.

attribute

A means of conveying additional information or metadata within a tag. Each attribute consists of a name="value" pair (e.g. <emph style="bold">).

baseline

A notional line on which characters and images are positioned.

binding

A typesetting action which forces a group of lines to be rendered together on the same column or page. If there is insufficient vertical space available then the whole group is rendered in a following column or page.

block

Rendered text corresponding to the content of a block element with paragraph breaks above and below. May be empty and may contain sub-blocks. See also fixed block.

block element

An element whose content is rendered as one or more paragraphs.

booklist

A file maintained within a TopLeaf partition containing links to the source XML for that partition.

box

A region of text surrounded by a rectangular frame. The appearance, position, shading and other aspects of the box can be controlled via mappings.

CALS

TopLeaf supports the CALS table model via a set of predefined mappings for tags such as <tgroup>, <colspec>, <row> etc.

cell

The lowest level container of a table. Each row consists of a number of cells. Cells are marked with the <entry> element in CALS tables, while HTML tables use <th> and <td> for header and data cells respectively.

change pages

Along with full looseleaf, one of the looseleaf methods supported by TopLeaf. Change pages is designed to minimize the size of the final document after each update is applied and is normally driven by changes to the printed output.

change bar

A margin rule set to indicate recently added/changed material.

child

In the XML hierarchy, an element which is immediately enclosed by the current element.

command

A construct similar to an XML element, which can be used within custom content to access TopLeaf functions not available via the dialogs. For example:

<rule width="2pc"/>
content model

In TopLeaf this term refers to how whitespace in the content of an element is handled. Available models are Element (ignore whitespace); Mixed (collapse whitespace to a single space); and Preserve (honor all whitespace).

crop box

A crop box is intended for publications where the final size of the paper is smaller than the paper that is initially printed. In other words, the paper is cropped after printing to remove the unwanted parts

CSS

Cascading Style Sheets: a form of style sheet used widely on the Internet. TopLeaf has some features in common with CSS, but CSS is directed towards screen display rather than paginated output.

custom content

Content specified in a mapping to be generated immediately before or after the normal element content. It can contain text, custom markers and/or commands.

custom marker

A construct similar to an XML element, which can be used within custom content to augment the markup present in a document. It can be mapped just like a normal element. Custom markers are defined by the user and generated as required to trigger appropriate actions in the typesetting, but have no effect on the actual source document.

custom table

A custom table is a structure that maps individual elements directly into a tabular format that conforms to the underlying publication table model.

data area

An area of the output page which contains data columns, and their associated sidenotes and margin rules.

data column(s)

One or more rectangular blocks on the output page which is filled by material from the input stream along with any required notes. Specifically excludes fixed blocks.

data flow / input stream

The natural flow of text and markup as the source document is processed. The term input stream refers to the XML source material being fed to TopLeaf, while data flow is the corresponding flow of material into columns of output. In a typical output page there are three classes of material:

  • Normal text and graphics, which appear in the input stream and are rendered in the same order in the output data columns.

  • Notes (e.g. footnotes, floats), which appear in the input stream but whose presence/placement is determined by the output layout (e.g. where a column ends). Thus they affect, and are affected by, the data flow but are not part of it.

  • Material which is neither part of the input stream nor of the data flow (e.g. fixed blocks).

In addition to the above, TopLeaf has facilities for suppressing, saving and re-using material from the input stream. This allows the order of material in the output document to vary significantly from the source document if required, and also allows the creation of secondary documents (e.g. table of contents, index).

decipoint

One tenth of a point (720dp = 1 inch = 2.54cm). This is the default unit for measures in TopLeaf.

derived change

Occurs when a looseleaf page is included in a release due to a change to the other page of the same leaf or in the publication style sheet.

descendant

In the XML hierarchy, any element contained within the current element.

differencing

Comparing the same page from different releases of the same publication, in order to locate new, changed or deleted material. TopLeaf allows differencing to be limited to a specific difference area of the page. This means that changes to headers that declare a release date will not be identified as different.

DITA

Darwin Information Typing Architecture. A form of XML markup in which documents are built up from small reusable topics.

DTD

Document Type Definition. A set of rules which specify what an SGML or XML document may contain. The DTD defines the elements and entities which may be used in a document and it also controls the order and context in which the elements may be used.

DTD-less

A TopLeaf partition is DTD-less if a DTD was not assigned when the partition was created.

element

In XML, an element is a specific portion of a document. It consists of a start tag, an end tag, and any enclosed content.

element content

The text and/or sub-elements contained within an element.

em

A printers’ measure equal to the point size of the current font. The width of the em rule and em space characters.

entity

In XML an entity is a named object in the form &name; Entities can denote characters or files to be included at that point in the document.

error

An abnormal condition arising during typesetting which may lead to some source material not being rendered (e.g. graphic file not found). See also fatal error and warning.

facing pages

Two consecutive pages viewed side by side as in an open book. Compare with leaf.

fatal error

An abnormal condition arising during typesetting which causes the immediate termination of the job (e.g. source document not found). See also error and warning.

filing instructions

A set of instructions for filing an update pack into a looseleaf publication, indicating which existing leaves are to be removed and which new leaves are to be inserted.

file entity

An entity which refers to a file other than the source document. The inclusion of a file entity normally indicates that the content of that file should be incorporated into the input stream at that point.

fill

A group of spaces, dashes, dots etc. which fills out a line of text. For example:

   Steak Dianne ........................................................... $21.50

fixed block

The area designated for material placed in a predefined position on the page, outside the normal data columns. Fixed blocks can contain material extracted from the input stream for the current pages (e.g. folio and telltales). Fixed blocks may take the form of headers or footers, but can appear anywhere on the page. The position of the block is fixed, the content is variable.

float

A collection of text/graphics whose rendering is deferred until the top or bottom of a data column. A typical use is for Figures, consisting of a graphic and title. Figures are normally printed at the top or bottom of the column to avoid disrupting the flow of the surrounding text.

font

A style of rendering printed characters. A combination of typeface, size and style effects such as bold, italic, underline.

(font) style

Variations which can be made to a typeface to invoke a specific font. The most common styles are bold and italic. Other styles include condensed (narrow characters) and black (super-bold).

footer

A fixed block positioned below the data columns.

footnote

A block of text printed below, and generally on the same page as, a reference point within a text column. TopLeaf supports both column footnotes which are printed at the end of the data column containing the reference point, and page footnotes which occupy the full width at the bottom of the text.

frame

A set of four rules (left, right, top and bottom) surrounding a box or table.

full looseleaf

Along with change pages, one of the looseleaf methods supported by TopLeaf. Full looseleaf minimizes the size of each update pack and is driven by changes to the source document content.

full release

In looseleaf publishing, a release pack which includes the whole document rather than just the updated leaves. This is the norm for electronic delivery, but may also be produced for a printed document.

graphic

An image which is rendered as part of a document.

GUI

Graphical User Interface. TopLeaf workstation can be used to design and change TopLeaf stylesheets and to manage looseleaf documents.

hanging indent

A style of indent in which the first line of a paragraph starts further left than the other lines.

header

A fixed block positioned above the data columns.

HTML (tables)

TopLeaf supports the HTML table model using a set of predefined mappings for tags such as <thead>, <col>, <tr> etc.

hyphenation

The action of breaking a long word over two lines to avoid short lines or excessive whitespace. TopLeaf includes hyphenation rules for most European languages. It also supports user supplied exception dictionaries for control of individual words and for specialist terminology (e.g. medical, legal). East Asian languages such as Chinese and Japanese do not use hyphenation as such, but do have special word breaking rules.

inch

One inch equals 2.54 cm, 72 points, or 720 decipoints.

index

A set of references to a document grouped alphabetically or by subject. TopLeaf has facilities for generating indexes automatically.

inheritance

The process whereby the typesetting properties of an element can be passed on to its descendants.

inline element

An element which is rendered as part of a paragraph, but which does not itself trigger the start or end of a paragraph (e.g. a hyperlink or italicized phrase).

input stream

See data flow.

intentionally blank

A filler page printed on the back of a leaf which contains only enough content to fill the front page. May be completely blank or contain a printed page number and headers and footers.

ISO

International Standards Organization. A body responsible for setting global standards in many fields. These standards are typically referred to by a number prefixed by ISO, ISO/IEC etc.

ISO 8859 — a family of 8-bit character sets that cover mainly the European languages. ISO 8859-1 (Latin1) is probably the most widely used — it covers most of the Western European languages.

ISO 8879:1986 — SGML

ISO/IEC 10646 — Unicode

justify

A line of text is (fully) justified when it is spread out enough to reach both left and right margins. See also alignment. TopLeaf justifies text by assigning an appropriate value to the interword space.

A page is vertically justified when the data columns run from the top of the page to the bottom. TopLeaf adds extra space between paragraphs and/or between lines to achieve this effect.

label

A small text fragment (such as a bullet, number or graphic), usually offset from an associated block of text and serving to identify that block.

label element

An element whose content is set as a label which automatically attaches to the following paragraph.

layout (editor)

The general shape of a page, including paper size, print area, fixed blocks, data columns etc. TopLeaf provides the Layout Editor dialog to control these properties.

leading

[Pron: ledding] A measure of line spacing, expressed in TopLeaf as the vertical distance between baselines of two successive text lines.

It is common practice to add extra leading to open out the text. Thus a document set in Arial 12/13 has a 12 point font set with 13 point leading. A document set in Arial 12/24 would be double-spaced (vertically).

leaf

A printed sheet of paper, as in the leaves of a book. Normally printed with the odd-numbered page on the front and the following even numbered page on the back. Single sided leaves can also be created if necessary.

leaf group

In a full looseleaf publication that uses a partition based numbering scheme, a leaf group identifies a set of adjacent leaves separated from another leaf group by a gap in the folio numbering sequence. Leaf groups are usually associated with a document structural unit. Leaf groups help minimize the number of generated point pages by reserving a leaf folio range into which the group may expand if required.

leaf indicator

A user defined string variable that can be used to hold metadata or typesetting controls for individual leaves.

leaf section

In a full looseleaf publication that uses a section based numbering scheme, a leaf section identifies a set of adjacent leaves that share a common section identifier. A section based leaf numbering scheme permits the division of the leaf numbering range into any number of separate sections, with each section containing any number of leaves.

legacy partition

A TopLeaf partition that declares content that is neither XML or SGML, or uses a component of TopLeaf that has been superseded.

legacy style sheet

A TopLeaf style sheet format that has been superseded.

letter

A character defined within a character coding system that represents an element of an alphabet.

line indent

An effect where the first or last line begins or ends at a different point to the remainder of the paragraph. See also margin.

link

A pointer to another part of the document or even an arbitrary location on the internet. In printed documents usually just a text fragment such as see section 3.1. In web pages, PDF files and other electronic documents is usually a hyperlink which, when clicked, takes the user to the indicated location.

link line

An identifier that indicates a gap in the page numbering sequence of a full looseleaf publication.

list-item element

An element whose content is rendered as part of a list and which generates its own label.

live pages list

Also known as List of Effective Pages. A list showing the current release number (or date etc) for every page or leaf in a looseleaf document.

log file

A file generated by the TopLeaf composition engine which gives by default a list of pages set, errors encountered, and job statistics. If debug mode is selected the log file contains much more detailed information.

looseleaf

A form of publishing where, rather than printing complete revisions of a document, the publisher produces only those leaves which have changed since the previous release. The recipient removes the old leaves and inserts the revised leaves. To facilitate this process the document is normally stored in a ring or lever-arch binder.

TopLeaf supports two different looseleaf models: full looseleaf and change pages.

Looseleaf publishing involves a number of complex processes: retention of leaf boundaries; correctly identifying differences; generation of point pages; consolidation of multiple revisions; page gapping; production of filing instructions etc.

mainwork

The initial (full) release of a looseleaf document before any updates are applied.

mapping

The association of a set of typesetting actions with a particular element or custom marker. The fundamental trigger for how TopLeaf renders each part of a document. For example the mapping for an <emph> element may simply be Set Italic On.

margin

The left and right margin settings determine how far from the edges of a column the text of a paragraph is set (see also line indent). The term Page margin is similarly used to define how far the printable area is set in from the edges of the page.

margin rule

A vertical rule running beside all or part of a data column.

marker

A tag or custom marker. Each marker can have an associated mapping.

markup

Metadata interspersed with text which serves to identify the structure and/or formatting of that text.

measure

A numerical value expressing a height or width. TopLeaf accepts measures in points, decipoints, picas, inches, centimeters, and millimeters.

merge

The act of physically combining two adjacent paragraphs into one output paragraph.

metadata

Data which is not part of the printed text of a document, but which indicates structure, format, or other relevant information about the text (such as creation date or index keywords). Metadata in XML typically appears in the form of tags, attributes and processing instructions.

mixed content

XML content which can contain text as well as elements.

newline

A generic term for a line end in the source document. May be a CR (carriage return) character, LF (line feed), or CR/LF. The content model determines if these characters are honored or ignored.

notes

The collective term for footnotes, sidenotes, floats and running heads. Notes appear within data columns.

orientation

The aspect ratio of the page when reading normal text columns: either portrait (like most books) or landscape (like most computer screens).

output document

The fully rendered output of a typesetting run. Can be accessed as printed pages or as a PDF document.

page

A single printed page or electronic equivalent. There are normally two pages per leaf (sheet of paper) printed front and back.

page gapping

Deliberately introduced breaks in the page numbering of a looseleaf publication so that new material has an area to expand into, avoiding the need to create point pages. For example, the page numbering for a document is structured so that new sections begin on every hundred page boundary. When the content is typeset, it creates a section ending on page 525, with the next section starting at page 601. A link line can be used to inform the reader that the gapping is intentional.

page group

In looseleaf jobs, an unbroken sequence of consecutively numbered pages. A group may contain sequences of point pages. See run.

page number

Can refer to one of:

  • folio / page ID — the number normally printed on the page and used to locate it in Tables of Contents etc. May be a simple number, or a string that reflects the document structure (e.g. C-47, 64.2.5). Blank and title pages may have no visible folio, while preface material may have roman numbering (i, ii, iii...);

  • sequence number — a number reflecting the order on which pages are produced, always a simple count (1, 2, 3...).

page type

The TopLeaf description of an output page layout, including paper size, margins, headers and footers, and placement of data columns.

pagination

The process whereby a stream of typeset text is divided into individual pages. Includes such aspects as page numbering, paragraph splitting, column management, footnote placement, generation of headers and footers etc.

paper size

The dimensions of the physical/virtual paper on which the output is rendered. The two most common sizes are Letter in the USA and A4 elsewhere. TopLeaf supports a range of predefined sizes and also lets you define your own.

paragraph

In TopLeaf terminology, a non-empty area of text between two block boundaries. More simply a single physical paragraph with no internal structure. For example a <para> element containing an internal <list> with four simple items consists of six paragraphs: the pre-list text, each list item, and the post-list text, if any.

The difference between paragraphs and blocks is that blocks (which correspond to block elements in the source) nest just like elements do. They can be empty or contain any number of sub-blocks. Paragraphs on the other hand do not nest or overlap and cannot be empty. An output document can be considered as a series of paragraphs, one after the other.

Can paragraphs be identified in the source document? Yes, but not as easily as blocks. In the example, the last “paragraph” would be the text between the </list> and </para> tags.

parent

In the XML hierarchy, the (unique) element which immediately encloses the current element.

partition

In TopLeaf, a partition refers to a subdivision of a publication corresponding to a single output document. A partition is the basic document unit processed by TopLeaf.

partition indicator

A user defined string variable that can be used to hold metadata or typesetting controls for a partition.

partition link line

A link line that appears at the end of a document in a fixed block advising the start page number of the next partition (ie. the next document that makes up the publication).

PDF

Portable Document Format A standard, developed by Adobe, which allows output documents to be stored in paginated form. This preserves the physical appearance of the finished document, which can then be viewed using Acrobat Reader or printed as hard copy.TopLeaf uses its own PDF builder to create PDF files. However, you will still need a PDF reader (e.g. Acrobat ™) to view these files.

Perl

A scripting language developed by Larry Wall. The TopLeaf composition engine provides a set of commands for passing data to and from an embedded Perl interpreter.

phase

The current state of a looseleaf document within TopLeaf, one of initial (prior to first publication), update (currently being modified) or published (release completed and locked).

pica

[Pron: pie-kah] A printers’ measure now accepted as 6pc = 1 inch = 2.54cm.

pixel

Short for picture element, a single dot on a screen. While images and web pages often use measurements in pixels, they are not suitable for the printed page as their physical size varies with the resolution of the display device. As a rough rule of thumb, 1 pixel = 1 point is a good starting value. However this simple conversion can give odd results when applied to hi-res images.

point

A printers’ measure (72pt = 1 inch = 2.54cm). Font sizes are usually expressed in terms of points.

point size (type size)

An indication of the size of the characters in a specific font.

point pages

New pages (created in full looseleaf only) to be filed between consecutively numbered leaves in the current release. For example new leaf 6.1–6.2 would be filed between existing leaves 5–6 and 7–8. Also called stroke pages if rendered as 6/1 rather than 6.1. Other forms such as 6a-6b are also possible. With double-sided leaves these pages always come immediately after the even numbered (back) page of the previous leaf.

print area

The area of a page within which all printed material appears. Controlled by the Layout Editor.

priority (of mappings)

A property of each mapping which causes that mapping to be selected ahead of mappings with lower priority.

processing instruction

A form of markup which, unlike elements, does not participate in the XML hierarchy. This allows it to be freely placed within a document to influence the processing at that point.

Has the form <?TARG CONT ?> where:

  • TARG is the target (ie. instruction name).

  • CONT is the (optional) content. The content is fairly free-form. It can resemble one or more attribute/value pairs, or simply be an arbitrary text string.

Note that the declaration at the start of a typical XML document:

<?xml version="1.0" encoding="utf-8" ?>

has the form of a processing instruction, but is treated as a separate type of object during XML processing.

property

A generic term applied to any of the numerous TopLeaf settings available through the dialogs. Some properties (e.g. Font Size) are fully inherited, some (e.g. Left Margin) are inherited as computed values, and some (e.g. Space Above) must be explicitly set on every element that uses them.

publication

A TopLeaf repository level consisting of a number of partitions. The stylesheets, DTD etc. are normally stored at this level and used by all contained partitions.

publish

A TopLeaf looseleaf function which produces the final version of the current release, creates the filing instructions and live pages list, sets a change lock on the partition to prevent further changes, and stores a copy of the release as a basis for change tracking.

published phase

TopLeaf maintains each looseleaf partition in two phases, the published phase and the update phase. The published phase is locked against further change and ready to be published, as distinct from the update phase which is still in preparation.

reference point

The point in the text where a footnote or sidenote is triggered. Footnotes typically place an identifying index number or symbol at the reference point. Sidenotes do not, as their position indicates which line of text is referenced.

release

The state of a looseleaf document once an update has been published. The initial release (or mainwork) is the whole document as originally published. Each release normally has a unique label which appears on all leaves updated by that release.

release line

A line printed on each leaf of a looseleaf release which indicates when the page was published. Typically contains the release name/number or publication date.

rendering

In general, the action of converting a source document into a fully paginated human readable format appropriate for the delivery medium. We use the term typesetting to refer to the internal process of assembling lines of text into pages. Thus a typesetting run generates the output pages, which can then be rendered on-screen, as hard copy, or as a PDF file.

TopLeaf repository

A directory folder in which TopLeaf stores publications.

row

The intermediate level container of a table. Marked as <row> in CALS tables and <tr> in HTML. A table consists of a vertical set of rows each consisting of a horizontal set of cells.

rule

A horizontal or vertical straight line. A horizontal rule drawn above or below a text paragraph is sometimes called a ruleoff.

run (of pages)

In looseleaf publishing, a number of new pages to be inserted as part of a release, which will appear in the publication as a continuous set of pages and which, therefore, can all be inserted into the publication by following a single line of the filing instructions. See page group.

running head

A continuation heading which is printed at the top of a page or a data column to indicate that a recent heading is still in force at a particular level. Running heads (unlike telltales) appear within the main data columns. TopLeaf provides up to five levels of running heads. TopLeaf can also produce running feet, which are lines indicating that the material continues in the next page/column.

segment

A portion of a page which is set as a unit. For example, a change from single-column to double-column text on the same page requires a new segment to be commenced. Column footnotes will be printed immediately at any change of segment, whereas page footnotes always appear at the bottom of the page.

SGML

Standard Generalized Markup Language. A markup language, which was adopted as an international standard (ISO 8879:1986), for marking up documents in such a way as to be independent of the software which created or which processes the document. TopLeaf can process SGML data, but most markup is now in the form of XML.

sidenote

A word, phrase or reference number which is printed to the side of a data column adjacent to the reference point.

soft hyphen

A special character (Unicode U+00AD) which is normally invisible, but marks where a word can be broken between two lines. If this happens, the hyphen will appear at the end of the first line.

source (document)

An XML document which is being rendered by TopLeaf. The source document may consist of a number of files that optionally reference separate graphic files.

string

A fragment of text without internal markup.

stylesheet

One or more files which indicate how a source document is to be rendered. TopLeaf stylesheets are processed using the TopLeaf workstation or can be edited directly.

table

A rectangular grid in which data can be arranged in a series of rows and cells. TopLeaf supports both CALS and HTML table markup.

table body

In a CALS or HTML table, a group of rows contained within the table <tbody> block.

table header

In a CALS or HTML table, a group of header rows contained within the outermost table <thead> block.

tag

In XML a tag is a unit of markup used to delimit elements within a document, and to convey metadata in the form of attributes. Tags come in three forms: the start tag <name>, the end tag </name> and the empty tag <name/>. Attributes may be carried by both the start and empty forms thus <name attr="value"/>.

tag-in-context

A tag name which includes some or all of the tag’s ancestors (e.g. /book/chapter/title). Used to distinguish between different occurrences of the same tag name, say between a chapter title and a section title.

telltale

An indicator rendered within a fixed block once the content of the page is known. For example, a dictionary header like aardvark–acumen would be assembled from two telltales defining the first and last term on the page.

transform

A process whereby material from the source document is substantially modified and/or re-ordered prior to rendering. TopLeaf can perform some transformations on the fly using a Perl extension. Other rendering systems require a preliminary transformation phase, using systems such as XSLT.

typeface

A set of printable characters with a specific look and feel (e.g. Times New Roman, Arial, Palatino). Combines with point size and style to define a specific font.

type size

See point size.

Unicode

A character coding system for assigning a unique number to all of the characters used in human languages, plus mathematical and other useful symbols. Every character is also assigned a general category and subcategory. The general categories are: letter, mark, number, punctuation, symbol, or control (in other words a formatting or non-graphical character). All XML documents specify an encoding which maps the byte sequences in the document to a set of Unicode characters.

Unix/Linux

Operating systems widely used for servers and for automated applications. The TopLeaf API is available for both 64 bit Linux and Windows versions.

update

A set of changes made to one release of a looseleaf document in order to create the next release.

update pack

A set of printed pages required to update a looseleaf document from one release to the next. Normally also contains a set of filing instructions and possibly a live pages list.

update phase

In TopLeaf, the stage at which a looseleaf release is in preparation. See also published phase.

US-ASCII

An encoding scheme for representing characters as 7-bit values. Can only represent the standard Latin alphabet, numbers, punctuation, and controls such as tab and newline.

UTF-8

An encoding scheme for representing Unicode characters as 8-bit values. US-ASCII characters are represented as themselves, whereas non-standard characters are denoted by sequences of up to 6 bytes. UTF-8 is typically used for European language documents, as most characters can be represented by a single byte. For languages with a large number of non-Latin characters (eg. Japanese), UTF-16 is usually more efficient.

UTF-16

An encoding scheme for representing each Unicode character as a sequence of 16-bit values (usually just one such value is sufficient). UTF-16 documents normally begin with a special byte order mark which identifies both the encoding and the order in which the originating machine has placed the constituent bytes. UTF-16 is typically used in non-European language documents, where there can be a significant size reduction compared to UTF-8.

value

A value is a string of text which can be interpreted as a number or measure. TopLeaf stores values internally as integers.

variable

A named area in which TopLeaf can store strings or values to be used in calculations or put back into the input stream at some later point.

W3C

The World Wide Web Consortium is a group of representatives of leading companies and other Web professionals that sanctions Web related standards such as XML, XSLT etc.

warning

An abnormal condition arising during typesetting which may lead to some source material being incorrectly rendered (e.g. attempt to set a margin outside the column boundary). See also error and fatal error.

whitespace

In XML input, those non-printing characters (newline, space, tab) which serve to separate words in the text. How whitespace is handled by TopLeaf depends on the content model of the current element, and is also affected by settings such as interword space. In an output document, any horizontal space between words or vertical space between lines.

widows and orphans

A widow line occurs when the first line of a paragraph stands alone at the end of a column or page, with the rest of the paragraph rendered at the top of the following column or page. A similar situation occurs when the last line of a paragraph stands alone at the top of a new column or page. This is known as an orphan line. Widow and orphan lines can also occur if column footnotes are permitted to split across a column or page boundary.

word break character

One of a configurable set of characters after which a word can be broken.. By default the only such character is the hyphen, but other characters (such as ampersand) can also be designated for word breaking.

XML

eXtensible Markup Language: a subset of SGML, sanctioned by the W3C, which removes much of the complexity of the older standard, while allowing the development of a number of associated standards and tools. Has largely replaced SGML as the standard of choice.

XML hierarchy

The arrangement of elements within an XML document in which every element (other than the topmost) is completely contained within exactly one parent element, and may contain zero or more child elements.

XSL-FO

XSL Formatting Objects are a form of markup, sanctioned by the W3C, in which partially processed documents can be stored prior to final rendering. Since TopLeaf processes source material directly, it has no need of an intermediate form of the document.

XSLT

XSL Transforms are a form of markup, sanctioned by the W3C, in which specifications for document transforms can be written. TopLeaf has a number of facilities for re-ordering and converting portions of the source document during processing, so a separate transform step is not usually required. However, in the event that a radical transformation is necessary, it is possible to use XSLT (or similar tools) on the document before passing it to TopLeaf.