In histograms for character and datetime columns, all column data is contained in double quotes. If the column itself contains the double-quote character, optdiag displays two quotation marks. If the column value is:
a quote "mark"
"a quote" "mark"
The only other special character in optdiag output is the pound sign (#). In input mode, all characters on the line following a pound sign are ignored, except when the pound sign occurs within quotation marks as part of a column name or column value.