1. Hex FF (11111111) when used as a delimiter or fence character. Usage: primarily at IBM shops.

2. [proposed] n. The Unicode non-character U+FFFF (1111111111111111), a character code which is not assigned to any character, and so is usable as end-of-string. (Unicode is a 16-bit character code intended to cover all of the world's writing systems, including Latin, Greek, Cyrillic, Chinese, hiragana, katakana, Devanagari, Thai, Laotian and many other scripts — support for elvish is planned for a future release).