Fair enough about passband attenuation -- sure, it's legit for a filter either to boost the resonance or to attenuate elsewhere.
in all likelihood it's an emulation of the lowpass species.
See, but this gets to my broader point: Why do you have to guess what kind of filter it is?
Why does the help patch not simply say explicitly that it's a lowpass filter?
This shouldn't even be a conversation. Just add one word to the help patch, and then the help answers rather than raises questions.
Same problem with [vcf~]'s help patch (re: "probably the right outlet of vcf~"):
0 signal: - the filtered signal (real part).
1 signal: - the filtered signal (imaginary part).
Now let's suppose you're a digital media artist with some degree of technical sophistication, but not quite enough mathematics to understand Julius Smith's digital filters book.
How, actually, is one supposed to guess, based on the information in the help patch, that real = bandpass and imaginary = lowpass? Oh right. I'm gonna spend a couple of months to grok Hilbert transforms until it finally dawns on me. Now that is user-friendly documentation.
If in fact it really is the right outlet of vcf~ (and it appears to be), then I shouldn't have to open the thread on the forum at all. I should be able to find the answer in the help. (I did look at the help patch before asking, but plainly the help is not written for PD's actual user base.)
FWIW I have a similar complaint with SuperCollider's documentation -- quite often, details are either missing or stated in terms that are not plainly relevant to the user's most likely question.