Type IIn supernovae (SNe IIn) are an enigmatic subclass of SNe that show heterogeneity in their photometric and spectroscopic properties. Complex, multi-component Balmer line profiles are a defining property of SNe IIn. Perhaps owing to the heterogeneity in the SN IIn class, online databases often conflict and hold outdated or erroneous classifications. This is compounded by SN “impostors” and H ii region contamination. We outline a classification scheme based on multi-component Hα profiles and apply it to a sample of 115 nearby (redshift z < 0.02) SNe that have held a SN IIn classification on the Open Supernova Catalogue (OSC). We find that 25 of our transients were misclassified as SNe IIn. We also note that there is disagreement between OSC and the Transient Name Server for 51 of the transients.

IIn 型超新星 (SNe IIn) 是 SNe 的一个神秘子类，在光度和光谱特性方面表现出异质性。复杂的多组分 Balmer 线剖面是 SNe IIn 的定义属性。也许是由于 SN IIn 类的异质性，在线数据库经常发生冲突并保存过时或错误的分类。SN“冒名顶替者”和 H  ii区域污染加剧了这种情况。我们概述了一个基于多分量 H α轮廓的分类方案，并将其应用于附近的 115 个样本（红移z < 0.02) 在开放超新星目录 (OSC) 上拥有 SN IIn 分类的超新星。我们发现我们的 25 个瞬变被错误分类为 SNe IIn。我们还注意到，OSC 和瞬态名称服务器之间存在 51 个瞬态的分歧。