IMEI and IMEI-SV have the same meaning. The only difference between them is instead of CD/SD (Check Digit and Spare Digit) it has SVN (Software Version Number).
Why it has been defined 2 terms explicitly by 3gpp because CD/SD was used to give the check of either UE is in black list or not. It is for stolen mobiles and all. Now it only depends upon the implementation. IMEI without CD/SD could also give the same results for verification. With SVN they have combined the software too. because in market there are some jerks who can change the IMEI code and will assign you the new one. Yeah.! This is possible. To avoid this, it is forced on UE manufacturers that while assigning this check either they are using IMEI-SV or IMEI. I guess in network it supports both.
ME-ID is totally different. It has to be defined separately because it is for CDMA. IMEI is used by all mobiles except CDMA. It is of 56 bits.
