Notes. For comparison, the nebular abundances of BD +30 (number fractions, Col. 7) are given as well (Pottasch & Bernard-Salas 2006). The mass fractions are normalised such that their sum equals unity; the logarithmic number fractions fulfil ϵ_EL = 12 + log(N_El∕N_H), where N_El is the number density of the element in question. The helium, carbon, and oxygen values of the WR composition in Cols. 3 and 4 correspond to those measured in the wind of BD +30 by Marcolino et al. (2007). Though the number abundances in Col. 4 are normalised to hydrogen in the usual way, their values still reflect the hydrogen-poor composition from Col. 3. The PN composition is typical for planetary nebulae in the disk of the Milky Way (e.g. Kingsburgh & Barlow 1994) and essentially solar with the exception of carbon and nitrogen because many nebulae (including BD +30) are somewhat self-enriched by processed matter. All elements not accessible to observations are assumed to have solar mass fractions.