From HEXONET Wiki
The AddDomainAvRecord command is used to create a Authentication and Verification (A/V) Data record. A/V records are only required for the .PRO registry at this point in time.
Additionally, the command can be used with the parameter
DOMAIN and without any additional parameters by anyone (not only by RegistrarOC customers) who has access to the submitted domain object.
(required) command = AddDomainAvRecord domain = (DOMAIN) or contact = (CONTACT) repository = (REPOSITORY) (optional) trigger= (TEXT) host = (TEXT) checktype = (TEXT)
(required) code = (CODE) description = (DESCRIPTION) (optional) property[avid] = (TEXT) property[roid] = (TEXT) property[createddate] = (DATETIME) property[avurl] = (URL)