there are alot of ways to join CID..... of cos the main one will
be thru application from CRC(career resourse centre) in the
intranet... but there will be no direct entry from TRACOM
itself.....
usually an officer needs to have some divisional experiance before
will be consider to be one of them... as for rank.... no rank
requirement too..... any rank can join them..... hope this
information helps.... 
cheers
'
its is not really possible to be TRANSFER to CNB or CPIB as they
are two diff depts from SPF. but we are under one HOME TEAM which
is the MHA(ministry of home affairs).... so u can apply thru your
dept and see what they advice you.... 
cheers
maybe u want to consider to setup one? 
=double post=