0444d588_18_FeatureList___FedoraProject__Summary
[% Complete] 100% [Name] KRB5 DIR: Credential Caches [Updated] 2012-09-26 [Summary] 
Kerberos 1.10 added a new cache storage type, DIR: which allows Kerberos to maintain TGTs for multiple KDCs simultaneously and auto-select between them when negotiating with Kerberized resources. Fedora should switch to using the DIR: cache format over the older FILE: cache format to support accessing mulitple Kerberos realms.
Releases/18/FeatureList - FedoraProject