Reply To: Rav Moshe Feinstein: Prohibition of social dating

Sacrilege, he means that while normally only close relatives or married women are considered an ervah (say, for the purpose of negiah), whereas other women are considered to be a penuyah (unattached) who have more lenient rules, that would not apply to women older than about 12. After that they are considered to be nidos, and the more stringent rules kick in.