Canadian Government Keyboard Standard for Information Technology Equipment Appendix A - Clarifications and Additional Details

This Appendix is a normative part of this standard.

The purpose of this Appendix is to clarify interpretation of the CAN/CSA-Z243.200-91, Canadian Keyboard Standard for the English and French Languages, to provide additional details regarding the CSA standard, and to specify certain details of the unaccented primary keyboard layout provided for in TBITS-5.

1. On a keyboard that is labelled in accordance with the CSA primary keyboard layout, function keys shall be labelled only with symbolic labels, and the symbolic labels shall be in accordance with ISO 9995-7.

2. A keyboard may use either the 47-key or 48-key geometry as specified in Figures 1 and 2 of the CSA Standard.

3. The following requirements apply to all keyboards:

3.1 The keys for the functions "level 3 shift", "control" and "alternate" shall be located in row A.

3.2 The function "group shift" may be implemented with a single key in row A, or with a combination of two or three keys in any rows.

3.3 The symbol on level 3 of key E00 of the CSA Standard shall be shown on the keyboard as a solid vertical bar, not as a broken bar. It is the character found at code point 7C hex/124 decimal in TBITS-3. Wherever it may be positioned on unaccented primary keyboard layouts, its representation should be as a solid vertical bar.

3.4 If printed, engraved or some other fixed form of keycap labelling is used, then the labels for graphic characters shall be placed on keys in accordance with ISO 9995-1. If liquid crystal display or some other variable form of keycap labelling is used, then the labels for graphic characters may be placed in another fashion.

4. The following requirements apply to all 47-key keyboards:

4.1 The key for the function "return" shall be located in positions C12 and C13. This is the key that normally generates a "carriage return/line feed".

4.2 The key for the function backward erase shall be located in positions E13 and E14.

4.3 The secondary keyboard layout shall be the same as the ISO 9995-3 common secondary keyboard layout with the exception of the lack of key B00.

4.4 Where the broken bar ( ) is available in an implementation's character set, access shall be provided to it. The broken bar is a character in the ISO common secondary keyboard layout (ISO 9995-3), and is found at code point A6 hex/166 decimal in TBITS-3; it is not the vertical bar (|) at code point 7C hex/124 decimal, which is commonly mislabelled on keyboards as a broken bar. Since the broken bar on key B00 of the ISO common secondary keyboard layout cannot be accessed in the 47-key version of any of the keyboard layouts, some other means of access to it must be provided and documented with the keyboard documentation.

5. The following requirements apply to the secondary keyboard layout:

5.1 The secondary keyboard layout is the complete "common secondary keyboard layout" as defined in ISO 9995-3, to the extent that a given implementation can support it. Each implementation will of necessity be character-set dependent, but shall implement all the functionality of the ISO common secondary keyboard layout that is feasible within the constraints of that implementation. This shall include duplicating functionality that may be present in either of the two primary keyboard layouts (CSA or unaccented). That is, if the character set or sets available to an implementation contain a character that is within the ISO 9995-3 group 2 character set, then the secondary keyboard layout shall provide the functionality to produce that character, whether or not that character may be labelled on a keycap and whether or not it may be available in either primary keyboard layout.

5.2 Labelling of the secondary keyboard layout is optional with either primary keyboard layout. Partial labelling as indicated in Figures 4 and 5 of the CSA Standard is acceptable in conjunction with the CSA primary keyboard layout. When the secondary keyboard layout is labelled in conjunction with an unaccented primary keyboard layout, all available non-spacing diacritics and all other available characters that are not duplicated on the unaccented primary keyboard layout shall be labelled.