What is a cap hold?
A placeholder charge (a multiple of last year's salary, by Bird status) that a team's own free agent occupies on its books until he re-signs, is renounced, or signs elsewhere. Holds keep teams from spending the same dollar twice: you can't use "his" room and then re-sign him with Bird rights. Renouncing clears the hold but forfeits the Bird rights.
2023 CBA · Art. VII §4
Why holds exist
Without holds, a team could spend all its cap room on outside free agents and then re-sign its own stars with Bird rights — double-spending the same space. The hold reserves a placeholder charge (a multiple of last salary) for an unrenounced free agent until he signs or is renounced.
One subtlety worth knowing: holds count against CAP room, but not against APRON calculations — hard caps are tested against signed salary only.
Common questions
How big is a cap hold?
A multiple of the player's previous salary based on Bird tier and salary size — from 120% up to 300% for cheap deals, capped at the max salary.
See it enforced, not just explained.
Build a trade or signing and the sim rules on it, with the relevant citation when one applies.