Group 1 - The article emphasizes the importance of issuing invoices in accordance with the law and regulations, highlighting that tax service institutions must issue invoices truthfully and accurately without engaging in fraudulent practices [3][4][5] - It outlines the specific tax service categories and their corresponding product codes that tax service institutions should use when issuing invoices, ensuring compliance with tax classification standards [4][5] - The article provides a detailed process for issuing invoices through the electronic tax bureau, including steps for logging in, selecting invoice types, and entering necessary information [6][7][8][10] Group 2 - The article specifies that tax service institutions without the qualifications of tax firms, accounting firms, or law firms are prohibited from engaging in certain specialized tax services, including tax consulting and compliance planning [5] - It includes a table listing various business types, their corresponding project names, and product codes, which serves as a reference for tax service institutions when issuing invoices [5] - The article also mentions the requirement for tax service institutions to handle invoice changes or cancellations simultaneously with any changes to their tax registration status [18]