Activate Symmetric Swapping

Activate Symmetric Swapping at U+206B is an invisible formatting character formerly intended to turn on mirrored treatment of paired punctuation in bidirectional text. It belongs to the General Punctuation block and has no normal standalone visual form; its effect, where recognized, concerns how surrounding characters such as parentheses, brackets, and angle brackets are displayed in right-to-left settings. This character is not used in modern everyday writing. It comes from an older Unicode bidirectional-formatting mechanism for texts that mix scripts such as Arabic or Hebrew with left-to-right material, where symmetric punctuation may need to face the reading direction. In contemporary text processing, the Unicode Bidirectional Algorithm, paired-bracket handling, and higher-level layout systems normally manage this automatically. The main place U+206B is encountered today is in legacy data, conformance tests, or documents produced by obsolete tools. Its most important practical gotcha is that it is invisible: if it survives in copied text, it may affect bidi rendering in unusual software or simply create a hard-to-see difference that complicates debugging, comparison, and cleanup.