A senator placing a hold in the U.S. Senate is theoretically required to identify themselves after six days, but this rule did not apply effectively when the hold was placed at the end of a congressional session.
Notes on verification
Confirmed by CRS/Congress.gov analysis of the 2007 Honest Leadership and Open Government Act, Senator Grassley's own press release criticizing the rule's limitations, and ProPublica reporting on a 2010 secret hold that killed whistleblower legislation without disclosure. [tier=bronze indep_score=0.539 clusters=2 claim_tier=notable]
Sources
- Which Senator Secretly Sabotaged the Popular Whistleblower ... (seed:politics_and_current_events)
- https://www.congress.gov/crs-product/R43563 (corroboration)
- https://www.grassley.senate.gov/news/news-releases/push-end-secret-holds-continues (corroboration)