It was available at https://www.ycombinator.com/documents/ until sometime between August 13, 2021 and August 19, 2021. The text above suggests that there should still be four documents, but now only three are shown.
Yes, I have a copy of it, but I'm wondering if YC is no longer 'supporting' the document.
In addition, the document itself includes the language:
"This Safe is one of the forms available at http://ycombinator.com/documents and the Company and the Investor agree that neither one has modified the form, except to fill in blanks and bracketed terms."
You're asked by the guidelines not to do this thing with titles. If you want your own title for someone else's article, write a short blog post referencing the original and take your chances submitting that.
Titles are community property. Your question belongs in a comment, not the title.
The proper title for this post is "Safe Financing Documents".
This particular case could alternatively have been suitably posted as an "Ask HN". Not every case could be.
The current submission only worked for me because I'd been to that page before and the submission title told me what to look for. Someone who doesn't know what to look for will be at best puzzled.
I think the title is correct but it should be a self post with the link in the text. They're trying to ask a question, not trying to introduce people to the safe financing documents.
Delaware is the gold standard, and I believe they prefer a Delaware C, but business friendly tax havens, and I believe many VCs are now able to invest in companies registered there. I think the Canada thing is just due to the number of Canadian companies that have gone through YC, but I could be wrong.
I think no US companies aren't required to be C Corps. That wouldn't make a ton of sense for them if they're planning to operate largely outside of the US.
I believe their system for non-US companies was to require that the actual (non-US) company is 100% owned by a Delaware corp, so the company operations and assets are legally "local" but all the relationships between founders, ycombinator and other shareholders are handled under Delaware law and contracts.