Restrictions on share transfers are common and can take almost any form. Such restrictions must be set out in the corporation$$s constitution and must be noted on the share certificate, otherwise

a$.$

the shares are not transferable.

b$.$

the shares have no value.

c$.$

any transfer will be ultra vires.

d$.$

the restrictions are not binding on a purchaser who has no notice of them

e$.$

a preemptive right is created