DESCRIPTION: This resource-limit limits the maximum number of samples that can be cached for a single instance and must be less than or equal to max_samples and greater or equal to the DDS_HistoryQosPolicy::depth.

: DDS_HistoryQosPolicy::depth determines how many samples are kept in case of DDS_TRANSIENT_LOCAL_DURABILITY_QOS durability and made available to late joining DDSDataReader, while DDS_ResourceLimitsQosPolicy::max_samples_per_instance is the maximum number of unacknowledged samples the DDSDataWriter can keep per instance. Thus, if max_samples_per_instance > depth it is possible to keep unacknowledged samples while limiting the number of samples made available to late joining datareaders.