However as the employment terms is primarily considered as a contract between employee and employer, you have to examine the sanctity of this with a contract expert or a legal professional.
Companies thrive on one key principle, "Fear Is The Key" they know that the poor employee will get scared with these unfair business tactics. Companies know that one single employee will not have guts and capacty to fight the might of a Corporate who has all the resources at there disposal.
Restrictive clause are product of such perverted thinking. Though such practices are illegal as in some cases courts have held it to be unfair and illegal.
Unless the specific instances are clearly and outlined with the logical reasoning, its illegal and unenforceable.
Motherhood statements of restriction are void ab initio.
The employee learns some thing new with every job, if every employer starts putting such restrictions there will be chaos. These restrictions violate right of employee to learn and exercise the acquired skill freely. Incompetent companies are scared of competition enforce such restrictions so that the employees are prevented from joining competition
I am personally against any such restriction.
Management should be made known by HR about this kind of policy and employment terms,instead of these absurd terms in employment clause.