I asked this question because I was learning regex in JavaScript, and one of the most popular websites I was using did not specify whether octal escape sequences were deprecated or not. At the time, I didn't know that octal escape sequences were deprecated.

However, I received the answer that octal escape sequences are now deprecated in JavaScript, and regular expressions no longer allow them. Instead, I can use hexadecimal (\xXX) or Unicode (\uXXXX) escape sequences without issues.