I don't recall the implementation here, but I do know that the spec's annotation support is prone to race conditions when creating anonymous caches. When it fails to find a cache and then creates one, this may fail when a concurrent call creates one first. The result is is an unhandled exception being thrown due to CacheManager lacking a getOrCreate(...) method for this purpose. It requires more care to make anonymous caches work, despite always being undesirable, then to disallow them entirely.

Sorry for not replying on the earlier ticket. I also don't think the JSR should have defined any configuration and hadn't thought it would be helpful to only contribute negatively.