beginner questions

dn: o=linuxfocus.org
o: linuxfocus.org
objectclass: top
objectclass: organization

dn: ou=editors, o=linuxfocus.org
ou: editors
objectclass: organizationalUnit

dn: uid=aghaffar, ou=editors, o=linuxfocus.org
uid: aghafar
cn: Atif Ghaffar
sn: Ghaffar
givenname: Atif
objectclass: person
userpassword: {CRYPT}yIvSBWSuLs2N2
mailacceptinggeneralid: aghaffar@linuxfocus.org
ou: editors

dn: uid=mkempe, ou=editors, o=linuxfocus.org
uid: mkempe
cn: Magnus Kempe
sn: Kempe
givenname: Magnus
objectclass: person
userpassword: clearpass
mailacceptinggeneralid: mkempe@linuxfocus.org
maildrop: mkempe@developer.ch
preferredlanguage: fr
ou: editors

Within a ldif file.

Then i followed executing the command:

ldapadd -D "cn=Manager, o=linuxfocus.org" -w secret < linuxfocus.org.ldif

I get the follow message:

adding new entry "o=linuxfocus.org"

adding new entry "ou=editors, o=linuxfocus.org"

adding new entry "uid=aghaffar, ou=editors, o=linuxfocus.org"
ldapadd: update failed: uid=aghaffar, ou=editors, o=linuxfocus.org
ldap_add: Undefined attribute type (17)
        additional info: mailacceptinggeneralid: attribute type undefined

Why occurs  that this fails at the update attempt and the message of 'Undefined attribute type'?

at my slapd.conf file I have configured:

 $OpenLDAP: pkg/ldap/servers/slapd/slapd.conf,v 1.23.2.5 2002/11/26 18:26:01 kurt Exp $
#
# See slapd.conf(5) for details on configuration options.
# This file should NOT be world readable.
#
include  /usr/local/etc/openldap/schema/core.schema

# Define global ACLs to disable default read access.

# Do not enable referrals until AFTER you have a working directory
# service AND an understanding of referrals.
#referral ldap://root.openldap.org

pidfile  /usr/local/var/slapd.pid
argsfile /usr/local/var/slapd.args

# Load dynamic backend modules:
# modulepath /usr/local/libexec/openldap
# moduleload back_bdb.la
# moduleload back_ldap.la
# moduleload back_ldbm.la
# moduleload back_passwd.la
# moduleload back_shell.la

# Sample security restrictions
#
#   Disallow clear text exchange of passwords
# disallow bind_simple_unprotected
#
# Require integrity protection (prevent hijacking)
# Require 112-bit (3DES or better) encryption for updates
# Require 63-bit encryption for simple bind
# security ssf=1 update_ssf=112 simple_bind=64

# Sample access control policy:
# Root DSE: allow anyone to read it
# Other DSEs:
#  Allow self write access
#  Allow authenticated users read access
#  Allow anonymous users to authenticate
# Directives needed to implement policy:
# access to dn.base="" by * read
# access to *
# by self write
# by users read
# by anonymous auth
#
# if no access controls are present, the default policy is:
# Allow read by all
#
# rootdn can always write!

#######################################################################
# ldbm database definitions
#######################################################################
database bdb
suffix "o=linuxfocus.org"
rootdn "cn=Manager,o=linuxfocus.org"
# Cleartext passwords, especially for the rootdn, should
# be avoid.  See slappasswd(8) and slapd.conf(5) for details.
# Use of strong authentication encouraged.
rootpw secret
# The database directory MUST exist prior to running slapd AND
# should only be accessible by the slapd/tools. Mode 700 recommended.
directory /usr/local/var/openldap-data
# Indices to maintain
index objectClass     eq

I hope someone can help me, and can tell me what is bad here.

Thank you in advance, Regards.