New classification: Western Subalpine Warbler is split from (Eastern) Subalpine Warbler C. cantillans following Zuccon et al. (2020) and Svensson (2013ab). The specific epithet is established as C. iberiae rather than C. inornata as the latter has been shown to be a junior synonym of C. subalpina (Zuccon et al 2020). Tentatively treat as monotypic, but the resident population of nw Africa (formerly inornata) is likely an unnamed subspecies (Svensson in litt).