Naming Rules :
Table names and column names:
Must begin with a letter
Must be 1–30 characters long
Must contain only A–Z, a–z, 0–9, _, $, and #
Must not duplicate the name of another object owned by the same user
Must not be an Oracle server reserved word
Use descriptive names for tables and other database objects.
Note: Names are case insensitive. For example, EMPLOYEES is treated as the same name as eMPloyees or eMpLOYEES.
For more information, see Oracle9i SQL Reference,“Object Names and Qualifiers.”