Recognition and probe-partition identification for probe H-free graphs
Determine whether probe H-free graphs can be recognized in polynomial time and whether the distinction between probes and non-probes can be determined for general graphs H.
References
However, for most graphs~$H$, the recognition of probe $H$-free graphs and the distinction between probes and non-probes are open problems.
— Colouring Probe $H$-Free Graphs
(2505.20784 - Paulusma et al., 27 May 2025) in Section 1, Introduction, subsection “Our Focus”