This procedure is defined in the server but not documented via ad_proc or proc_doc and may be intended as a private interface.
The procedure is defined as:
proc acs::cache_flush_pattern {cache pattern} {
#
# Provide means to perform a wildcard-based cache flushing on
# (cluster) machines.
#
foreach n [ns_cache names $cache $pattern] {
ns_cache flush $cache $n
}
}