A short-term revolving facility (also called a capital call line or fund-level revolver) collateralized by LPs' uncalled commitments, used by the GP to fund investments and expenses before issuing capital calls — typically repaid quarterly or at milestones. By deferring the start of the LP IRR clock by 6-12 months, sub-line usage can boost reported net IRR by 100-200 bps, all else equal — this is the principal IRR-manipulation vector flagged by ILPA, which has called for clearer disclosure of sub-line usage and tenor.