pools, the Public Service Commission runs a number of specialized competitions to recruit recent university graduates, such as the Post-Secondary Recruitment (PSR) program to staff entry-level. Other competitions seek to attract academics or individuals with extensive experience in policy work, such as the Recruitment of Policy Leaders (RPL) and Emerging Talent Pool (ETP) programs to the federal workforce, placing successful candidates in more senior, mid-career positions. In addition, managers can select candidates through a non-advertised appointment of former participants in Government of Canada student employment programs to an entry-level position. This process known as 'student bridging', and is responsible for about 16.6 per cent of all indeterminate hires, according to the Public Service Commission. Student employment The Public Service of Canada recruits high school, undergraduate, and graduate students for full- and part-time paid internships, through various sources, including the Federal Student Work Experience Program (FSWEP), the Research Affiliate Program (RAP), and co-op programs at post-secondary institutions in Canada. As of March 2020, the Public Service of Canada employs around 8,852 students. Unlike most public servants, students do not occupy a 'substantive position' and therefore are unable to participate in internal recruitment processes. They are additionally are ineligible for vacation leave and are not represented by a union. Students are only eligible for these internships if they are registered as full-time students at a Canadian secondary or post-secondary institution. For summer or other work term positions, they must demonstrate they are registered for classes in the next semester to meet the requirements for employment. Job classifications Positions within the public servants are organized into occupational groups, which are divided further into job classifications and sub-groups. As of 2020, the Core Public Administration has about 31 occupational groups, covering 56 job classifications. Occupational groups and job classifications are typically referred to by a two-letter code, such as FS, used for foreign service positions. The specific duties and expectations of each job classification is determined through different policy instruments. Before the reorganization of the public service during the latter half of the 20th century, public servants were organized into hundreds of different occupational groups, with one survey of civil service positions by American consultants identifying nearly 1,700 unique classifications within the federal government in 1921. The arrival of the Public Service Employment Act, in preparation for establishing collective bargaining for public servants, saw a concerted effort to consolidate and reorganize position classifications to