Appendix B: Glossary of terms and abbreviations

baseline In typography, the imaginary line on which characters sit. The x-height of a font is measured from the baseline to the top of a lowercase x. The descender, for those characters that have one, is defined as the portion of the character that falls below the baseline.

Bezier curves Named after the French mathematician Pierre Bézier, Bezier curves utilize at least three points to define a curve. The endpoints are called the anchor points, while any other point is known as a node. The curves produced by RML's <curves> tag are Bezier curves.

bitmap A bitmap is a way of storing an image. In bitmaps, each pixel ("picture-cell") is stored as one or more bits of data in a "map" consisting of rows and columns. This means that when you print them out at the size they were created at they look fine, but shrinking or enlarging them leads to them looking blocky and ragged.

JPEG and GIF are both bitmapped graphics formats (as are BMP, PICT and PNG). You can use gifs and jpegs in your RML document with the <image> tag. see also "gif", "JPEG", "image"

Boolean Named after the nineteenth-century mathematician George Boole, Boolean logic is a form of algebra in which all values are reduced to either TRUE or FALSE (or 0 and 1).

CMYK A way of specifying a color by its Cyan, Magenta, Yellow and Black ('Key') components. Usually used when referring to pigments - such as in printing.

DTD Document Type Definition. A term from XML that refers to the file that defines the legal building blocks of an XML document, and the permissible ways to structure it.

empty elements "Empty" elements are those tags that don't have any content, and are closed with a "/>" at the end of the same tag rather than having a separate closing tag. (e.g. <getName id="Header.Title"/> doesn't have a separate </getName> tag - the "/>" serves to close it so it doesn't need one). Empty elements are also sometimes known as "singletons".

fill In RML, the color that a graphic or text item is filled with (as opposed to that of its outline or stroke).

flowables In RML, "flowables" are items which appear in a story (such as paragraph, spacer, and tables). Flowables are positioned in sequence running down a frame until there is no more room left in that frame, when they are placed in the next frame (or on the next page if necessary). They can not be mixed with graphics. Flowables include the following tags: para, blockTable, title, h1, h2, h3, spacer, illustration, pre and plugInFlowable. see also "graphics"

GIF GIF (Graphics Interchange Format) is a bit-mapped graphics file format created by CompuServe in 1987. It is still in common use on the World Wide Web and many other places today. You can use gifs in your RML document with the image tag. see also "bitmap", "JPEG", "image"

graphics In RML, "graphics" are items which can appear inside the pageGraphics and illustration tags. Unlike flowables, graphics are explicitly positioned on the page by co-ordinates. They can not be mixed with flowables. see also "flowables"

HTML The Hyper-Text Markup Language. The language used for writing pages on the World Wide Web.

image In RML, the "image" tag allows you to use existing graphics files in your document. Currently image supports the GIF and JPEG formats - the two most common formats on the World Wide Web. Most paint applications support both the GIF and JPEG standards. see also "bitmap", "GIF", "JPEG"

JPEG A lossy compression technique for color images created by the Joint Photographic Experts Group (JPEG). Better for photos than the GIF format, it can use up to 24-bit color and reduce file sizes to about 5% of their normal size. JPEG files are widely used on the World Wide Web and many other places. (The JPEG format is sometimes known as JFIF, JFI, and JPG as well as JPEG). You can use JPEG files in your RML document with the image tag. see also "bitmap", "gif", "image"

jpg See JPEG.

leading Leading (pronounced "ledding") is the amount of vertical space allotted for a line of type - the distance between the baseline of one line to the baseline of the next. The name comes from the way that printers used to use thin strips of lead or brass to separate the lines of metal type. In RML, leading can be supplied as an attribute for the para and paraStyle tags. It is expressed as the height of the line plus the space between lines. So, for example, using a 12 point font with a leading of 18 gives you a space between lines of 6 points. You can also have negative leading. By giving a number smaller than the size of font you are using, you can arrange it so that the lines overlap each other.

orthogonal An adjective from mathematics meaning "relating to or composed of right angles". A non-orthogonal transformation is one which does not preserve right angles. skew is a non-orthogonal transformation.

PDF The Portable Document Format. A format created by Adobe, this is a standard for electronic documents which is platform-independent due to the freely available Acrobat reader. The PDF file format is a complex indexed binary format, with a specification 600 pages long. (RML is much easier!)

RGB A way of specifying a color by its Red, Green and Blue components. Usually used when referring to lights - such as on a computer screen.

RML Report Markup Language. An XML dialect, created by ReportLab, Inc, and and used by their software rml2pdf to produce documents in PDF.

singletons See "empty elements".

story The part of an RML document where the main content of a document goes (if it uses the "template/stylesheet/story" form). This is where text - split into paragraphs by <para> tags - is put.

stroke In RML, the color of the outline of a graphic or text item (as opposed to that of its inside or fill.)

stylesheet This is an obligatory part of an RML document. It is where the styles for paragraphs and blockTables are defined (though it can be empty).

template In those RML documents that use the "template/stylesheet/story" form, this is the part of the document where any headers, footers, or background graphic elements are defined.

vanilla Plain, ordinary, or standard [from the default flavor of ice cream in the U.S.] In RML, you can put in letters, numbers, and punctuation in places which allow you to use "vanilla text", but tags such as <para> or <b> are not allowed.

whitespace For programmers, whitespace refers to all the characters that appear as blanks on your screen. This includes the space and tab characters, linefeeds, carriage returns, and other more specialised characters. For designers, whitespace is any areas on a page that aren't the content - the bits that are free of text or artwork.

XML The Extensible Markup Language - a document processing standard set by the World Wide Web Consortium (W3C) - the people who defined the standard for HTML.