splitIndex.maxPercentChange::
	When the split index feature is used, this specifies the
	percent of entries the split index can contain compared to the
	total number of entries in both the split index and the shared
	index before a new shared index is written.
	The value should be between 0 and 100. If the value is 0, then
	a new shared index is always written; if it is 100, a new
	shared index is never written.
	By default, the value is 20, so a new shared index is written
	if the number of entries in the split index would be greater
	than 20 percent of the total number of entries.
	See linkgit:git-update-index[1].

splitIndex.sharedIndexExpire::
	When the split index feature is used, shared index files that
	were not modified since the time this variable specifies will
	be removed when a new shared index file is created. The value
	"now" expires all entries immediately, and "never" suppresses
	expiration altogether.
	The default value is "2.weeks.ago".
	Note that a shared index file is considered modified (for the
	purpose of expiration) each time a new split-index file is
	either created based on it or read from it.
	See linkgit:git-update-index[1].