`TCustomFiler`
pt		GetIdentifier
pt		GetDescription
		Create
		Destroy
		SupportsFeature
		OpenStream
		CloseStream
		ReadHeader
		ReadRecord
		GetAtRecord
		GetFieldValue
		GetFieldCount
		GetOptionCount
		GetOptionName
		GetOptionAsString
		GetOptionAsInteger
		GetOptionAsBoolean
		HasOption
		SetOptionAsString