So far, whenever I have wanted to express the fact that the ‘POST-OSL’ equivalents of words such as EME maken were words such as ma:ke, I have been talking in terms of ‘vowels’ and their counterparts, without giving due consideration to metalanguage. Of course, such terminological carelessness has its drawbacks. Take, for instance, the very term Open Syllable Lengthening itself. Though basic to my considerations, it is not nearly as straightforward as it might seem. Thus, it can be read both as ‘lengthening of something (in our case: vowels) in open syllables’ or as ‘lengthening of open syllables’. Now, this terminological ambivalence reflects that phenomena such as OSL might not only be conceived as lengthenings of vowel segments (implying that all the higher constituents in which a vowel figures get lengthened with it), but equally well as changes of syllable quantity that just happen to show in their nuclei, so that the vowel lengthenings could be regarded as sheer epiphenomena. A further possibility of viewing OSL is suggested by Minkova, whose version of OSL clearly implies that the change might be understood as a foot restructuring in which a foot of two light syllables came to be replaced by a foot of one heavy syllable. One aspect of these alternative interpretations is that both the syllable-based view of OSL and the foot-based one make sense only within a phonological theory that recognizes other descriptive levels than that of linear segmental organization.