The request to rename for example in S-300 Grumble.
Rockets had such indexes (are located by date of development):
5B55K, 5B55KD - radiocommand management.
5B55R - more perfect with increased Range (it was directed if I am not mistaken, television way).
The rocket "Favorit" has an index 48N6E2.
But that there was no mess suggest to name the weapon - "S-300".
Rus web page SA-10 Grumble
Rus web page SA-11 Gadfly ( 9K37 Buk )