L1- B Visas Intracompany Transferee Visa
Just like L-1A, L-1B visas are available only to those temporary workers who have worked for the duration of at least one year for the foreign subsidiary or daughter company of the US company. L-1B, however, are available for those employees who have specialized knowledge of that particular company.
L-1B applicant has to prove that he/she possesses unique knowledge about the company, its operations or product. The ground for US company to apply for such visa is that it cannot find a worker with that unique knowledge on the US job market. The law allows larger size companies to file “blanket” petitions covering an entire group of such employees with no name, where the names shall be identified later.