Hi all, the SRM v2.2 docs are here: http://sdm.lbl.gov/srm-wg/ Quoting from that, with adjustments: --------------------------------------------------------------- The Retention Policy represents the quality of retention, which indicates the probability of the storage system losing a file. Replica quality has the highest probability of loss, but is appropriate for data for which a certain amount of loss can be tolerated, in particular when other copies can be accessed in a timely fashion. Output quality is an intermediate level and is appropriate for data which can be replaced by lengthy or effort-full processes. Custodial quality corresponds to low probability of loss. --------------------------------------------------------------- Thanks, Maarten