Some musicians write extensions (except for the first one) between parenthesis. Thus, they would write G7(>9)
instead of G7>9
, and D7(<9<5)
instead of D7<9<5
. This way of notating can be seen in The New Real Book. But apart from that publisher, not a lot of publishers use this method. Here is een example of Take the A Train:
Using parenthesis do not really help in making the chords more readable. I would advise starting musicians to leave them out.