Several characters could be used as combining characters, when preceded or followed with a backspace C0 control. This is attested in the code charts for IRV, GB, FR1, CA and CA2, which note that "',^ would behave as the diaeresis, acute accent, cedilla and circumflex (rather than quotation marks, a comma and an upward arrowhead) when preceded or followed by a backspace. The tilde character (~) was similarly introduced as a diacritic (˜). This encoding method originated in the typewriter/teletype era when use of backspace would overstamp a glyph, and may be considered deprecated.
