You can use double quotes within identifiers.
If the QUOTED_IDENTIFIER database option is set to OFF, double quotes are used to delimit SQL strings and cannot be used for identifiers. However, you can always use square brackets to delimit identifiers, regardless of the setting of QUOTED_IDENTIFIER.
The default setting for the QUOTED_IDENTIFIER option is OFF for Open Client and jConnect connections; otherwise, the default is ON.
For details, see Chapter 3, “SQL Language Elements,” in the Sybase IQ Reference Manual.