Parenthesis

Some musicians tend to write all extensions after the first extension 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 books 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.