Here are different types of share restrictions as per law in Pakistan:

Pre-Transfer Restrictions

1. Pre-emptive Rights: Existing shareholders’ right to purchase new shares or existing shares being transferred.
2. Drag-Along Rights: Majority shareholders can force minority shareholders to sell their shares.
3. Tag-Along Rights: Minority shareholders can force majority shareholders to sell their shares.

Transfer Restrictions

1. Lock-up Agreements: Shareholders agree not to transfer shares for a specified period.
2. Non-Compete Clauses: Shareholders may be restricted from engaging in competing businesses.
3. Non-Disclosure Agreements: Shareholders may be required to maintain confidentiality.

Post-Transfer Restrictions

1. Right of First Refusal: Existing shareholders have the right to purchase shares before they are offered to outsiders.
2. Call Option: Company or shareholders can require purchase of shares.
3. Put Option: Shareholders can require sale of shares.

Regulatory Restrictions

1. Securities and Exchange Commission of Pakistan (SECP) Regulations: SECP regulates share transfer procedures and imposes restrictions.
2. Companies Act 2017: The Companies Act 2017 imposes restrictions on share transfers.
3. Listing Regulations: Listed companies must comply with listing regulations.

Other Restrictions

1. Shareholder Agreement: Shareholder agreements may impose additional restrictions.
2. Board Resolution: Board approval may be required for share transfers.
3. Share Transfer Form: Completion of share transfer form may be required.

Grounds for Nullification

1. Non-compliance with company law: Non-adherence to Companies Act 2017, SECP regulations, or private company’s articles of association.
2. Invalid share transfer form: Incomplete, inaccurate, or unsigned share transfer form.
3. Lack of board approval: Share transfer without board approval.

Consequences of Violation

1. Invalid share transfer: Share transfer deemed invalid.
2. Penalties: Directors, officers, or shareholders may face penalties or fines.
3. Loss of rights: Transferee loses acquired rights.

For accurate information and updates, consult:

1. Securities and Exchange Commission of Pakistan (SECP) website.
2. Federal Board of Revenue (FBR) website.
3. Certified public accountants (CPAs) or company secretaries.
4. Business consultants.
5. Legal professionals specializing in corporate law.

Please note that laws and regulations may change. Consult official sources for updates.