To be compliant with entry-level ANSI SQL, identifiers cannot:
Begin with a pound sign (#)
Have more than 18 characters
Contain lowercase letters
Adaptive Server supports delimited identifiers for table, view, and column names. Delimited identifiers are object names enclosed within double quotation marks. Using them allows you to avoid certain restrictions on object names.
Use the set quoted_identifier option to recognize delimited identifiers. When this option is on, all characters enclosed in double quotes are treated as identifiers. Because this behavior is incompatible with many existing applications, the default setting for this option is off.