Quotation marks, from the way they look when written: 66 99. Mainly used in the learning processes of young children. Example: When you are quoting someoneput sixty-six and ninety-nine around what they said.
SIXTY-SIX AND NINETY-NINE
Meaning of SIXTY-SIX AND NINETY-NINE in English
Slang English vocab. Английский сленговый словарь. 2012