Another wording which I find easier to understand would be a modification of the new sentence introduced by Xyne from: "The quorum is counted among TUs who are active throughout both the discussion period and the voting period."
to: "The quorum is counted among TUs who are active at the point of time the voting is started at the AUR but every TU is allowed to vote."
If a TU then becomes inactive during the vote and prior to casting his or her own vote, he or she would still count towards the quorum, which doesn't make sense. Second proposal:
The quorum is normally counted among TUs who are active from the beginning of the discussion period until the end of the voting period. Other TUs may participate in the vote if they wish, in which case they shall be among those counted to establish quorum.
Example: * 20 active TUs during the whole procedure (start of discussion to end of vote): quorum is 14 (0.66 * 20, rounding up) * 2 new and one inactive TU decide to participate: quorum becomes 16 (0.66 * 23, rounding up) The second sentence thus prevents skewed quorums.