Hello,
By design, Read Only Domain controllers does not replicate all attributes, those which aren’t replicate are called “Filter Attribute Set” (FAS), you can find them with that PowerShell example :
$dse = [adsi]“LDAP://RootDSE”
$SchemaPart=$dse.schemaNamingContext
$RODCFASSearcher=[ADSISearcher]”(searchFlags:1.2.840.113556.1.4.803:=512)”
$RODCFASSearcher.SearchRoot=[adsi]”LDAP://$SchemaPart”
$RODCFASSearcher.FindAll() | Select-Object -ExpandProperty Path | % {($_ -split “,”)[0]} | % {($_ -split “=”)[1]} | Sort-Object