Cluster-safe, sprayable, single-server session cookies (DomAuthSessId)
When enabled by setting the new notes.ini DominoSessionCookieUniqueNames=1 the name of the DomAuthSessId cookie becomes DomAuthSessIdABCDEFGHIJK, where ABCDEFGHIJK is the first 11 characters of Base64url [SHA256 (Domino server DN)]. This causes multiple Domino servers that are all serving the same internet site to choose unique cookie names instead of overwriting each other's cookies.
This functionality is disabled by default due to concerns about breaking current applications and sprayer rules with special logic for cookies named "DomAuthSessId".