Question
Which objectclass is univentionInventoryNumber Assigned to?
Answer
Have a look in the univention schema file /usr/share/univention-ldap/schema/univention.schema
Searching for the interesting attribute will show entries defining the objectclass:
objectclass ( 1.3.6.1.4.1.10176.70 NAME 'univentionHost'
SUP top AUXILIARY
DESC 'Univention host'
MUST ( cn )
MAY ( macAddress $ aRecord $ aAAARecord $ mXRecord $ cNAMERecord $ associatedDomain $ univentionNetworkLink $ univentionInventoryNumber $ univentionOperatingSystem $ univentionOperatingSystemVersion))
The objectclass univentionHost uses the attribute univentionInventoryNumber.