Just in case you think I've made a hobby of looking for suggestions like this, I'm simply translating the thing right now and being a jurist myself, I immediately see some things that need fixing. When I feel an urge to spend my free time looking for problems in website ToS-es, I'll go and have my head duly examined. This said, the current rule read:
Using the discussion area, the answer posting form or the answer explanation box to comment on another's suggestions is not allowed.
While the rule has a worthy goal in mind, which is to a void a tooth and nail kind of competition, I believe it ignores the benefit of comparing answers and explaining the differences e.g. as to whatever nuance they focus on or whatever presumptions or methods the answerer is adhering to—even if the asker is asking for it. In fact, the discussion area hardly has any use other than brainstorming and comparing the answers, so perhaps the inclusion of the discussion area in the ban was not appropriately thought through before it was mandated. The agree/disagree/neutral commenting system is insufficient for the purpose I described here (not in the least because it is limited to 255 characters only!), just in case such an argument is raised. It is all the more impractical when you have 4 or 5 proposals to handle. It would be similarly impractical to resort to profile messages or e-mail to keep conversations behind the stages.
The rule is dead on PLEN KudoZ right now, as in it is neither followed nor enforced, while unwarranted attacks on others' proposals are rare or nonexistent (let alone ad hominems). (Curiously, 'discussion area' is missing from the current Polish version of the rules, so perhaps it didn't catch up on an update.)
In short, please fix the rule. I suggest:
Using the discussion area, the answer posting form or the answer explanation box to comment on another's suggestions without a really good reason is discouraged.
The 'discouraged' part is also in keeping with the spirit of the rules that discourages some less than welcome things (e.g. guessing at answers, giving more than one answer to the same question) without banning them outright, perhaps in recognition of the possibility that there might sometimes be a good reason for doing that. The same holds true in this case all the more.
Backing up peer comments with references, in general, is encouraged.
As far as I've noticed, you can't post a ref once you've posted an answer. You can't stick a reference – e.g. an MLA citation – in the 255-character limit you have to justify your agree/disagree/neutral comment. This isn't feasible.
[Edited at 2013-07-25 10:44 GMT]