@inproceedings{zhai-etal-2026-abstain,
    title = "Abstain-R1: Calibrated Abstention and Post-Refusal Clarification via Verifiable {RL}",
    author = "Zhai, Haotian  and
      Liang, Jingcheng  and
      Kang, Dongyeop",
    editor = "Liakata, Maria  and
      Moreira, Viviane P.  and
      Zhang, Jiajun  and
      Jurgens, David",
    booktitle = "Findings of the {A}ssociation for {C}omputational {L}inguistics: {ACL} 2026",
    month = jul,
    year = "2026",
    address = "San Diego, California, United States",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/ingest-acl/2026.findings-acl.985/",
    pages = "19674--19695",
    ISBN = "979-8-89176-395-1"
}