String 

OS_AUTHENT_PREFIX = authentication_prefix 

Static 

Operating system specific (typically "OPS$") 

OS_AUTHENT_PREFIX specifies a prefix that Oracle uses to authenticate users attempting to connect to the server. Oracle concatenates the value of this parameter to the beginning of the user's operating system account name and password. When a connection request is attempted, Oracle compares the prefixed username with Oracle usernames in the database.

The default value of this parameter is OPS$ for backward compatibility with previous versions. However, you might prefer to set the prefix value to "" (a null string), thereby eliminating the addition of any prefix to operating system account names. 

Note: The text of the OS_AUTHENT_PREFIX parameter is case sensitive on some operating systems.  

• Oracle Advanced Security Administrator's Guide for more information on setting this parameter.

• Your operating system specific Oracle documentation for the default value.