We document how explicit employer requests for applicants of a particular gender enter the recruitment process on a Chinese job board. We find that 95 percent of callbacks to gendered jobs are of the requested gender; worker self-selection ("compliance" with employers' requests) and employer callback decisions from applicant pools ("enforcement") both contribute to this association, with compliance playing the larger role. Explicit gender requests account for over half of the gender segregation and gender wage gap observed on the board. Ad-level regressions with job title and firm fixed effects suggest that employers' explicit gender requests have causal effects on the gender mix of applications received, especially when the employer's likely gender preference is hard to infer from other contents of the ad. Application-level regressions with job title and worker fixed effects show that both men and women experience a callback penalty when applying to a gender-mismatched job; this penalty is significantly greater for women (44 percent) than men (26 percent).