Ah, sorry about that, during the first Jams there was actually a little different system.
Right now, we use pretty simple 1/(rank+1) system, which means that 1st place gets 1/2 score (0.500), 2nd gets 1/3 (0.333), 3rd gets 1/4 (0.250) and so on. Every unranked entry gets plain 0 points. In that regard, no matter how many entries you rank, you give the same score to your top picks.
Earlier, we used so-called "normalised" 1/(rank+1) system, which more or less worked the same way except for one thing - the unranked entries were treated as if each got the next rank after the last entry. So, if you rated 10 games, then the 10th entry got 1/11 score (0.091) and all the unranked ones would get 1/12 score (0.083).
Well, technically speaking, there was an extra step of subtracting the unranked entries score from all the ranked ones. So, the first entry would get 0.500 - 0.083 = 0.417, then the second 0.333 - 0.083 = 0.250, then the third 0.250 - 0.83 = 0.167 and so on till the 10th entry, which would get 0.008 score. Though whether the unranked entries scores were subtracted or not didn't change the overall standings. It was more so that unranked entries would stay at 0 points, which is more intuitive than a bunch of entries magically getting a score of 0.083, even though the reviewer didn't really like them.
Somewhere along the way, the normalised ranking was ditched in favour of the regular one. First, because the normalised ranking was particularly "punishing" for 3rd places in typical 3-rank Jam (if reviewer only rated top 3, they'd give the first place measly 0.050; it's 4-5 times less than what would be given with full ranking). Second, because the problem the normalised was trying to address - some people would play only several games or so and they would rank their least favourite entry "above" all the ones they didn't play - that problem turned out to be less relevant during recent Jams. Now it seems most reviewers try out all the entries at least a little (even if they don't rank all the way), so such a measure is not as necessary anymore.
So yeah, you are correct; that remark was a leftover that somehow slipped our radars until now. I'm going to remove it from the current voting topic, so that maybe it won't cause any more confusion. ^^'