This variable is new in 6.5.4
SPR# SVRO63SNKW - Increased the default max design cache from 1GB to 2GB,
increased the default max number of elements from 400 to 800.
Also added the following Notes.ini variables to override these defaults:
GNCACHE_MAX_SIZEKB - this specifies the maximum size in kilobytes that the
in-memory design cache should be allowed to be before items start to be
DESIGNCACHE_MAX_ELEMENT - this specifies the maximum number of elements that
should be allowed in the in-memory design cache before items start to be
purged. The defaults in the code used to be 1000 KB and 400 elements. The code
now uses defaults of 2000 KB and 800 elements.
This used to be 400, is set in 6.5.4 onwards to 800
Lotus Notes/Domino 6.5.4