# Key concepts: Comparison matrix DQ2 vs. Rucio

Features | DQ2 | Rucio
--- | --- | ---
File identifier | GUID/LFN (Basename) | Scope + Label name
Dataset identifier | DUID/DSN | Scope + Label name
Versioning | Yes | No
Namespace | Global/Flat | Scoped
Unique PFN | No | Yes
Overlapping dataset | Yes | Yes
Storage Element Groups | No | Yes
Storage Element Tagging | No | Yes
Quota support | Group | Account (Group/User)
Dataset Replica completeness | Yes | No
Meta-data name-space/support | System defined, Data placement | System-defined, Physics, Production, analysis, Data placement
Data discovery unit | Pattern | Meta-data
Data operation unit | Dataset | Dataset, File
Multiple replica ownership | No | Yes
Dynamic placement | No | Yes
Replication rule support | No | Yes
Hidden data | Yes | Yes
Reuse of dataset name | No | No (but possibility to resuscitate dataset)
Notifications | Yes | Yes
Fine-grained accounting | Partially | Yes