Postdoctoral applicants struggle to navigate unclear supplementary material submission rules across different institutions

Postdoctoral candidates face confusion about whether they can submit additional recommendation letters beyond what's explicitly requested in application guidelines, with no clear institutional guidance on acceptable supplementary materials. This ambiguity creates anxiety about application competitiveness and risks rejection for non-compliance, while current solutions (asking advisors informally, guessing) are unreliable and time-consuming during an already stressful application cycle.