The submission, excluding title page and bibliography, must not exceed 10 pages (authors should feel free to send submissions that are significantly shorter than 10 pages.) If 10 pages are insufficient to include a full proof of the results, then a complete full version of the paper (reiterating the material in the 10-page abstract) must be appended to the submission after the bibliography. The length of the appended paper is not limited, and it will be read at the discretion of the committee. A detailed proof in the appended complete version is not a substitute for establishing the main ideas of the validity of the result within the 10-page abstract.If I'm reading this right, you can't just shunt certain proofs and exposition to an appendix, as was previously done. You have to make an entire full version of the paper and append it to the shortened version. Is that correct ?
Update (7/5): I have an update from Yuval Rabani, the PC chair, which resolves the question (in the affirmative):
This is an experiment I introduced in response to conflicting attitudes in the PC. The idea is that some PC members would like to read the entire paper, and it's hard to follow the paper when you have to jump back and forth between the 10 page abstract and the appendix. So the idea is that most committee members will just print the 10 page abstract, and those
interested in the entire paper will print the attached full version. Since this is an experiment, I don't intend to enforce the guidelines very strictly, but if it's not too much of an effort on your part, we do prefer a submission according to the rules.