Level 1 liquid assets
From ACT Wiki
Bank regulation - liquidity
Level 1 liquid assets are those of the highest liquidity quality.
Level 1 liquid assets are mostly high quality central government obligations, with a Credit Quality Step (CQS) of 1, and certain other qualifications.
They are eligible for inclusion in the calculation of a bank's High Quality Liquid Assets (HQLAs) either in full, or with only a small haircut.