Evidence is presented that suggests that articulation should be considered separately from acoustics (or the auditory impression) in investigations of the interface between phonetics and phonology. We use Ultrasound Tongue Imaging to show that onset and coda versions of Dutch /r/ can have secondary articulations, categorical allophones, and subtle or covert articulations which have few acoustic implications. Covert rhotic (retroflex) articulation was observed in one speaker, who displayed acoustic derhoticisation. We also consider this finding in relation to ongoing work in Scottish English.caslpub2745pu