Before using this attribute, you need to be sure, that your directory server actually supports atomic increments (LDAP Modify-Increment). See [https://www.iana.org/assignments/ldap-parameters/ldap-parameters.xhtml Lightweight Directory Access Protocol (LDAP) Parameters] and [https://tools.ietf.org/html/rfc4525 Lightweight Directory Access Protocol (LDAP) Modify-Increment Extension (RFC4525)].
The following search should tell you, if you LDAP server supports the LDAP Modify-Increment Object Identifier Descriptor (OID 1.3.6.1.1.14):
<source lang="bash>
ldapsearch -H ldaps://ldapm.stepping-stone.ch -b "" -s base -D "cn=Manager,dc=stoney-cloud,dc=org" -W \* + | grep 1.3.6.1.1.14
</source>
<source lang="text>
supportedFeatures: 1.3.6.1.1.14
</source>
<source lang="text>
If * is listed, all user attributes are returned. If + is listed, all operational attributes are returned.
</source>
=== Billing ===