* the service must recognize <code>ETag</code>, <code>Last-Modified</code> and <code>Cache-Control: none</code> provided by the client and act accordingly.
* every answer to a GET request must include proper <code>Cache-Control</code> headers
''Implementation notes'':
* one could use the internal LDAP attributes <code>entryCSN</code> and/or <code>modifyTimestamp</code> to generate an ETag via a hash function. In the case of business objects where multiple LDAP objects are aggregated for one exposed object, the hash can be generated over all constituent objects
* the <code>Last-Modified</code> header can be used to directly limit the search results when hitting the LDAP via the <code>modifyTimestamp</code> internal attribute. Ex. <code>modifytimestamp>=20060301000000Z</code>
=== Resources and HTTP methods ===