Interestingly, I moved my lazy fingers to check it out and found there are five click releases with dedicated symbols in the International Phonetic Alphabet (IPA): bilabial , dental , palato-alveolar or "palatal" , (post)alveolar or "retroflex" !, and alveolar lateral .
I have a couple of local, South African friends who speak Xhosa (if I recall). Think I'll check it out, more.