Some Private Use Area code points for courtyard codes.

This document is an index and an introduction to some documents which list some Private Use Area code points for a set of elements for organizing various aspects of text display using computing equipment in a Unicode environment.

Although intended for use in computing generally, one particular usage is for use by Java programs which are broadcast to televisions in relation to the DVB-MHP (Digital Video Broadcasting - Multimedia Home Platform) system and some of the code point allocations are provided specifically with that system in mind.

These lists, the code points being entirely the choice of the present author, are published by the present author. The code points chosen are only as consistent amongst end users as end users choose to make them. These code points are not a "standard". They are simply provided on the basis that a list is better than no list, in that the existence of a list will hopefully help in the application of computing in a Unicode environment.

These codes, named courtyard codes, are devised to resolve a number of circumstances in a hopefully useful manner.

Readers are asked to note that the approach of using individual codes to designate items such as GREEN and 36 POINT is regarded as not the best approach to use by some experts in applying the Unicode system. The alternative is to use a system of markup. However, my own view is that for some applications it is simply better to have an individual code point for a command such as GREEN rather than have to use a markup sequence of several characters which sequence then needs to be decoded by software, rather than the software just acting upon one character. It is possible that readers may choose, upon studying the matter, to use markup methods rather than individual code points, thus not making use of the code points in this list. However, in the event that a reader decides that, for a particular application, he or she prefers to use individual code points, then he or she may like to consider using this set of code points. There are two possible advantages to using this particular set of code points. The first is that the information is ready to use. The second is that if various people each use this set of code points rather than each devising his or her own set of code points, then the possibility exists of interoperability of programs and files produced by various people.

The choice of the name courtyard codes is because any code point allocations within the Private Use Area of the Unicode system are necessarily non-exclusive definitions, so, in order hopefully to be of assistance to end users, including myself, in providing a consistent method of using the Private Use Area I am asking that users of the Private Use Area might kindly agree to not use the range U+F300 through to U+F3FF for other code point allocations unless they feel that there is some overwhelming need to do so.

If such a consensus amongst end users happens to occur, then a protected courtyard will be produced which will hopefully be of benefit to everybody who makes use of the Private Use Area.

Certainly, the standards bodies will, by their previously stated policies, not endorse any particular designations within the Private Use Area. However, not endorsing is very different from being against, and I have no reason to think that an agreement amongst end users in this matter will be seen as going against any standards policy, as long as that agreement is only amongst the people who agree and that there is no attempt whatsoever to say or even to imply that anyone should not use those code points for some other purpose. It is all very fragile, yet, with care, it might just work!

I realize that I am asking a huge thing here, yet it seems to me that if everyone were voluntarily to agree to avoid using that area for anything else, then some of the codes within that area could be used to provide a classification mechanism which could potentially be of great usefulness to everybody. I realize that classifying the Private Use Area from within itself with one hundred per cent certainty is impossible, yet I feel that it is worth a try at setting up a voluntary system which could work if everybody agrees to it, even tacitly agrees by just avoiding using the U+F300 to U+F3FF range for anything else, in the hope that some benefit may be realized.

The codes in the U+F300 to U+F37F range are used for providing a guide, if desired, to which particular set of code point allocations, by anyone, anywhere, are being used for Private Use Area code points in the same document which are not within the U+F300 to U+F3FF range.

The codes in the U+F380 to U+F38F range are used for various symbols which will hopefully be of general usefulness.

The codes in the U+F390 to U+F3FF range are used to provide fairly commonly used formatting at a basic level. A few codes within this section are added especially to support the use of Java programs using the DVB-MHP system.

Most of these codes do not produce the display of a glyph themselves, but provide instructions which affect the display of other characters, namely of those characters following themselves until such time, if ever, that the display rendering system receives some later instruction affecting that aspect of the display.

So, for example, if GREEN and 36 POINT are used, then subsequent text is to be displayed in green at a size of 36 point. If a command RED is then received, then subsequent text is to be displayed in red at a size of 36 point, though the text already displayed in green stays in green. If sometime later a command 18 point is received, then subsequent text is displayed in red at a size of 18 point, though the text already displayed stays in 36 point.

However, a few of the codes, do produce a display themselves, these are the code points from U+F380 to F38F. They provide a few special symbols which might be useful generally.

Programmers need only implement those codes which they need for any particular application. So, for example, a general graphics program need not implement the displayable symbols.

Please note that all codes are not being added initially, as finalising the details of some of them and preparing documents has not yet been completed.

William Overington

2 July 2002

List of available documents, some added after the above date, please see the dates on the individual documents.

Some Private Use Area code points for courtyard codes for choosing collections of code points.

Some Private Use Area code points for courtyard codes for accumulator management.

Some Private Use Area code points for courtyard codes for text ligatures and swash characters.

Some Private Use Area code points for courtyard codes for text colour.

Some Private Use Area code points for courtyard codes for text formatting and style.

Some Private Use Area code points for courtyard codes for text size.

Some Private Use Area code points for courtyard codes for special functions.