Share transfer restrictions:  you can make a rzbl ag. that…
a.  rt of first refusal/option to purchase
b.  buy-sell ag. (if SH offers sale, corp. must buy-back)
c.  push-pull:  either you buy my stock or I’ll buy yours – O’or sets price (“Texas shoot-out”)
d.  requires shareholder to consent to transfer of shares
e.  prohibits selling shares to certain types of ppl.
f.  keeps you as an S corp.
*  must be conspicously noted on share certificates