International Council on English Braille (ICEB)

Unified Braille Code Research Project

Objective II: Extension of the Base Code

Supplementary Report
by the
Objective II Committee

October 15, 1999
(corrections through January 9, 2000)


This report is supplementary to the principal report of Committee II, dated March 2, 1995 (corrected through June 22, 1995), and covers all the additional work and changes made since that report was published. Consequently, except for changes specifically detailed here, that earlier report still applies.

For the period covered by this report, the members of the Objective II Committee were:

A separate UBC Symbols List is a companion to this report, providing an up-to-date list of the symbols defined for UBC (except for grade 2 and certain special modes). See that list also for information on settings and/or fonts that may be required for best viewing of the braille characters in this document.


By motions adopted in December 1995 and March 1997, the Committee defined a special mode of UBC known as "alignment mode".

The purpose of alignment mode is to accommodate those relatively rare cases where there is a compelling reason to give physical arrangement issues, notably horizontal space taken and the vertical alignment of symbols, priority over the preciseness and richness of representation that normally characterizes UBC. Specifically, alignment mode provides for a regime in which each of the 64 braille characters represents a print character. In other words, there are no multi-cell signs; the normal rules of UBC symbol formation are suspended.

Examples of such cases, i.e. where physical arrangement MIGHT be an overriding need, would be: (1) spatially arranged hexadecimal arithmetic and (2) displaying computer reports or computer screen arrangements in such a way that the physical layout is precisely preserved for analysis. Neither of these examples absolutely requires alignment mode, because it would always be possible to use regular UBC multi-cell representations for the various characters and still keep them aligned, if there is sufficient horizontal room. However, alignment mode provides an alternative when there isn't room or a 1-to-1 representation is deemed important for other reasons.

Within alignment mode, the normal set of defined symbols is given in the following list. The assignments are designed for maximal compatibility with normal UBC; other reasons are given within parentheses:

Alignment mode should be used only when alignment on a symbol-by-symbol basis is important throughout groups of symbols on the same line, as in the working layouts mentioned. It is not needed and should not be used in cases such as tables, outlines, and computer programs where the alignment applies only to groups as a whole, usually to the beginnings of groups (e.g. to a column of names that are left-aligned within the column).

When considering the use of alignment mode, it should be taken into account that alignment mode is inherently ambiguous--for example, there is no way to distinguish the case of letters. Sometimes such ambiguity does not affect the essential meaning of the material--"a" and "A" normally have the same meaning as hexadecimal digits, for instance. But if the meaning is affected, alignment mode must be avoided and standard UBC used, even though a wider layout may result.

All in all, alignment mode is to be used rarely.

If print symbols not on the standard alignment-mode list appear in a physical layout that is to be transcribed in alignment mode, braille characters corresponding to unused symbols may be reassigned and explained in a transcriber's note.

Alignment mode is signalled by the following entrance and exit symbols:

These symbols are proper UBC symbols, do not clash with other assignments, can stand alone on a line without physical ambiguity, follow the same entry/exit conventions that have been established for typeform indicators, and lastly suggest, through the repeated vertical dot patterns, that this mode has something to do with vertical alignment.

There is an unavoidable technical ambiguity that is inherent in any exit symbol for alignment mode, because all 64 possible braille characters, even those used strictly for prefixes in mainstream UBC, have been assigned a meaning in alignment mode, consistent with its purpose. So the exit symbol could theoretically mean "vertical line, vertical line, apostrophe", for instance. With the assigned exit symbol, the probability of such ambiguities arising in real cases was judged extremely low.

Because of the special way that braille characters are used in alignment mode and the fact that the normal UBC symbol formation rules are not followed, alignment mode is in some ways more like a distinct code than a part of "proper" UBC. For this reason, only the entry and exit symbols for alignment mode are normally listed with standard UBC symbols.


By motion adopted in July 1996, the Committee established a second type of "dot locator" symbol, namely

to be used when the locator is present only to avoid physical ambiguity (i.e. to make sure the reader can correctly sense which dot patterns are present), as contrasted with the usual role of the dot locator to "mention" the symbol as well as to disambiguate the dot positions.

When the traditional "mention" dot locator (already assigned as

in the March 1995 report) precedes a symbol, it implies that that following symbol is being discussed, i.e. "mentioned", and that it does not have its usual force. So if the following symbol is the grade 1 passage indicator, for instance, it does not actually switch the interpretation of the succeeding symbols to grade 1. When translating braille to print, it would be natural to represent the braille symbol that follows a locator in some way in print--e.g. by dot numbers, or by showing the dot configuration using a font for "simulated braille".

When the "use" dot locator precedes a symbol, it merely ensures that the braille reader is able to read that following symbol; it has no effect on the meaning of that symbol. So if the following symbol is the grade 1 passage indicator, for instance, there is a switch to grade 1 interpretation, just as when the dot locator is not present. When translating braille to print, a "use" locator would be ignored.

"Mention" locators occur only when braille is being discussed as a subject--as in this document, and in braille instruction manuals, for example. In literature generally, they would occur infrequently.

"Use" locators would be useful whenever a braille symbol needs to be isolated in space, so that the braille reader could not otherwise tell what dots are present. For example, a colon (dots 2-5) that is far from surrounding text could not readily be distinguished from a hyphen (dots 3-6) or the letter "c" (dots 1-4). For the most part, braille is designed so that such cases rarely arise, but since they can arise, the "use" locator is expected to be useful though infrequent. Probably the most common use will be to allow grade 1 passage opening and closing indicators to be isolated on lines by themselves, thus leaving the line-by-line arrangement of enclosed material (such as computer programs) aligned more naturally.


By motion adopted in October 1996, the Committee adopted a set of standard UBC symbols to be used for representing lines or segments of lines in diagrams, as in structural chemical formulae. To do so, it was necessary also to change the assignment of the "new line" indicator (typically used in poetry) from that given in the March 1995 report, and to constrain contraction usage slightly (though not so that any real words are affected). The full text as adopted is given in the numbered paragraphs below:

1. The "line sign" (dots 3-4-5, section 3.15 of the March 1995 report) is to be reassigned to @\ and the restriction that the sign must be surrounded by spaces is to be removed.

2. In any word that consists entirely of the letter-groups "ar" and "gh" catenated in any order, or that commences with three or more such groups, no matter how capitalized, the first "gh" or "ar" must not be contracted.

3. Horizontal lines: To draw a horizontal line (other than the hyphen, dash and minus sign, which are separately defined): (a) for horizontal lines indistinguishable from a dash, including simple horizontal chemical bonds, the dash symbol ,- should be used. (b) In other cases, the symbol "3 begins a special "horizontal line mode". Thereafter, all nonspace UBC symbols other than \ are interpreted as line-drawing characters, intended to convey the type of line being drawn, corners etc. This horizontal line mode continues through all such symbols, up to (but not including) a following \ symbol or space. A \ symbol would signal the beginning of an arrow (as already defined), deemed to be continuous with the line, and upon termination of the arrow, horizontal line mode would resume. A space would restore ordinary text mode. Within horizontal line mode, the following symbols should be used where applicable:

Valid UBC symbols other than those listed above, and excluding \ and space, may also be used as necessary to convey distinctive types of lines. In general, it is the physical shape of the line or feature (such as a junction) that should motivate the choice of symbol, rather than the meaning of the symbol in other contexts.

4. Vertical lines: Vertical line segments are drawn using _ ,_ or ^ symbols. _ is always for a single solid line segment, the others for variants (e.g. dotted or dashed) as needed. One or more such symbol may occur in a group, but each such group must be surrounded by spaces. This is in effect an assignment of all symbols so formed, when surrounded by spaces, to represent vertical line segments or groups of such segments. The standing assignment of _ (when followed by space) to the underlined passage terminator is not changed, but is further restricted to require that the preceding symbol must not be a space. The same further restriction is applied to the standing assignment of ^ (when followed by space) as terminator of bold passages. Arrows vertically contiguous with vertical lines so constructed are deemed to be continuous with them.

5. Diagonal lines: Diagonal line segments are drawn using > ,> < and ,< symbols, the first two for right-leaning diagonal lines and the second two for left-leaning ones. The single-cell symbols are always for single solid line segments, the others for a variant type (e.g. dotted or dashed) as needed. One or more such symbol may occur in a group, but each such group must be surrounded by spaces. This is in effect an assignment of all symbol groups so formed, when surrounded by spaces, to represent diagonal line segments or groups of such segments. The standing assignments of < and > to braille grouping enclosures are not changed, but are restricted to usage where groups of enclosure symbols are not surrounded by spaces. Arrows vertically contiguous with diagonal lines so constructed are deemed to be continuous with them.

6. The diagonal line symbols are to be used for vertical line segments at points where the vertical lines are crossing or otherwise too near diagonal lines to permit the required space between the two kinds of lines.

The following points were noted with respect to these "line" provisions:

There seems to be only one "word", namely AR (as in the postal abbreviation for Arkansas) that matches the definition of provision 2, and it had already been determined that a contraction would not be used in that case because it conflicted with the line sign as previously assigned. So provision 2 will not result in any real contraction loss, and will allow line drawings to be used in grade 2 as easily as in grade 1, without indicators or ambiguity.

Similarly, there is no real loss in the added restriction, in provision 4, that the passage terminators _ and ^ cannot be used when preceded by space. The second of these cases would never come up in practice (for there is no such thing as a "bold space"), and surely passages that end in an underlined space would be uncommon. And since the full terminator _' can always be used, even that uncommon case is covered.

And again, the added restrictions on enclosure symbols in provision 5 do not constrain any actual need, since it would never be necessary or desirable to have enclosure symbols surrounded by spaces (recalling that they are braille indicators, and so need not be spaced from the symbols they enclose). (By implication, enclosures could never be used to enclose line segments, which would not be sensible anyway given the different purposes of the two devices.) Enclosures and lines could very well coexist in the same diagram, and would do so without ambiguity as to which is which.

The Committee also noted that the technology for producing "real" tactile lines -- for example, by using paper especially coated so that arbitrarily drawn lines can be raised by heat -- is advancing rapidly. Methods are being developed that enable blind persons to compose graphics, either directly (e.g. using "pens" with heated tips) or through adapted computer-assisted drawing (CAD) programs. All this means that even better ways of doing tactile diagrams may often be available. However, there no doubt will remain many practical situations where it will be useful to employ ordinary braille cells, spaced as in regular text, for diagrammatic purposes (a view that is reflected in the BANA chemistry code, for instance). These provisions are meant to allow for that case, and by no means to discourage more advanced means of producing diagrams when they are practical.


By motion adopted in January 1999, in response to the evident wishes of braille readers to preserve the use of the current single-cell quotation marks in all nontechnical cases, not just in "larger works", the Committee relaxed the relevant rule as stated in the March 1995 report accordingly.

The original (March 1995) rule read:

The nonspecific quotes, that is those that are not distinguished as to whether they are "double" or "single" or "Italian", may be used at the transcriber's discretion for the predominant quotation marks in larger works, in which case a transcriber's note would clarify which specific kind of mark was intended.

That paragraph was altered and two new paragraphs added, so that the rule now reads:

The nonspecific quotes, that is those that are not distinguished as to whether they are "double" or "single" or "Italian", should be used for the predominant quotes in all instances where the specific form of quotation marks has no technical significance (that is, in the great majority of cases).
When non-specific quotes are used in a document, their use should include all instances of that form of quote that meet the criteria of the previous paragraph, e.g. both outer quotes and second-level inner quotes.
When practical, it is desirable to provide nonintrusive means by which the braille reader can determine the original form of quotes, even in nontechnical cases. Transcriber's notes, inclusion on special symbols pages, or any other such means of providing the information are encouraged, as permitted by the production context.


By motion adopted in March 1999, the Committee assigned UBC symbols for the print currency symbols used for the new "Euro" and also the Nigerian Niara. In order to maintain consistency in symbol patterns, the UBC symbols for the set-membership operators "reverse element" (i.e. "contains the element") and "is an element of" (i.e. "belongs to") were reassigned at the same time. The resulting symbol assignments are:


At this writing (October 1999), a set of chemistry-related symbols has been proposed but not yet acted upon. The Committee expects to take these up next, and expects also to revisit certain mathematical subjects (notably Geometry) where the assigned symbol set may need to be expanded to provide adequate coverage.

ICEB contact information
ICEB home page
Page content last updated: January 9, 2000