Unable to add attribute to cn

["Frank, Hans, 232" <Hans.Frank@bamf.bund.de>]

Hi there,

I would like to add the attribute "orclnetdescstring" to the following
ldap object:
cn=TESTDB,cn=OracleContext,dc=test,dc=de

When trying this, I get the following error message:
09:44:42 AM: Failed to add 'orclnetdescstring' attribute for
ldap://***:389/cn=TESTDB,cn=OracleContext,dc=test,dc=de
Root error: [LDAP: error code 65 - attribute 'orclnetdescstring' not
allowed]

I did include the attributetype into the core.schema, which is included
in slapd.conf the following way:

attributetype ( 1.3.6.1.4.1.9232.6 NAME 'orclnetdescstring' 
        DESC 'Oracle-OID spezific A-Type' 
        SUP name 
        ) 

or:

attributetype ( 1.3.6.1.4.1.9232.6 NAME 'orclnetdescstring' SUP name )

But that doesn't change anything. I am very new to openldap, so if there
are any good tutorials which describe such simple things (I suppose this
is something simple), please let me know.

I just need this object with some specific attributes, how can I realise
this?

Best Regards
Hans Frank