6.2. How Keystrokes Work
Mozilla's XUL supports the <keyset>, <key>, <commandset>, and <command> tags. These tags are used to associate keys with GUI elements and to process keystrokes when they occur. These tags allow key assignments to be changed on a per-document or per-application basis. XUL also supports the accesskey attribute.
A key is a small bit of plastic on a keyboard, with some printing on it. Keys can be divided into two rough groups: those with an equivalent glyph and those without. A glyph is a visual representation, like A. The Unicode standard handles keys that have glyphs; for nonglyph keys, like Control-C, there is almost no standards support.
Mozilla's support for keypresses predates the DOM 3 Events standard. That standard ...