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 nsmcp::track {object} {
variable temporary
variable temporarySerial
if {![info exists temporarySerial]} {set temporarySerial 0}
set lifetime request:[incr temporarySerial]
::nsf::var::set $object __nsmcpRequestLifetime $lifetime
dict set temporary $object $lifetime
}