Open, the site's label. The bounds in hand are $n^{1/2}\ll f(n)\le n^{3/5+o(1)}$. The lower bound is elementary: the greedy argument of Baltz, Schoen and Srivastav (p. 172, $f(n)\ge\sqrt n$; Colloq. Math. 86 (2000), refereed) and the interval construction the site credits to its discussion thread ($f(n)\ge2\sqrt n-2$). Choi's $f(n)\ll n^{3/4}$ and his conjecture $f(n)\le n^{1/2+o(1)}$ (1971, not held) are attested by Erdős 1973 and by the 2000 paper, whose Theorem 2 gives the best refereed upper bound found, $f(n)=O((n\log n)^{2/3})$; both are accepted partial claims, on Choi's claim page (1971) and the claim page of Baltz, Schoen and Srivastav (2000). The bound $n^{3/5+o(1)}$ is the site's own account: a reduction to the independence number of a random Cayley sum graph sketched in the thread, combined with Theorem 4 of Alon and Pham's 2025 preprint (independence number $\tilde O(p^{-3/2})$; arXiv:2509.02561v1), which the site's commentary adopts; the conjectured $\tilde O(p^{-1})$ would give $n^{1/2+o(1)}$. That route has no claim page: it is a reduction posted in the thread (20 January 2026), not a dated manuscript; its input is a preprint theorem that does not mention the problem; and the two Lean files linked from the thread take that theorem as an assumption. A full proof claim on the site's tab (19 July 2026) claims $c\sqrt{n\log n}\le f(n)\le n^{1/2+O((\log\log n/\log n)^{1/3})}$, hence $f(n)=n^{1/2+o(1)}$, in a manuscript whose abstract ends "This proposed solution was found by GPT-5."; the site's label was OPEN on 2026-09-18 and on 2026-10-06, and its commentary does not adopt the claim, which is recorded as a pending full claim on its claim page (Wang, 2026) with the manuscript's own provenance and its Lean development, which the corpus has not built. The frontmatter standing derives from that pending claim.