Well, for a second year course I did last semester, attendance was marked off in week 3 at a random time to make sure everyone was there for a special presentation about labs (we were e-mailed a few days beforehand), week 7 we were checked off on the last day to see who turns up (we were given notice the lecture before only so it catches out the people who don't attend), week 8 after the midsem there was a special presentation which we were told a few days prior we would be checked off, then we had a substitute lecturer in week 10, whom got our names checked off, then in week 12 we had the substitute who had us check off (and even threatened to count the numbers of checked off and those at the lecture, which although would do nothing, it stopped me and two others marking off 5 people each haha).
But yeah, the only intention of doing so was so that if you managed to get 49 and attended all lectures and tutes, the course convenor would bump your mark up a bit to let you pass. Also, it was used for cut-offs at 64, 74, 84, etc.
Nice lecturer/course convenor.
If you didn't turn up to anything, and you only just missed out on a HD or DN or CR or PS, then no sympathy was given