As I am not able to either add a comment or propose changes (which apparently would be required to re-open the question) to the question “Requiring salary information and medical history before first job interview [on hold]” below, I will post my comments here.
The actual question, “Is it common – or legal – in Japan to require itemized salary information from your current or previous position and medical history as a precondition for continuing the selection process?” is both answerable and clearly not ”seeking advice on company-specific regulations, agreements, or policies”. The question is “seeking advice” on what is common or legal in Japan, not Rakuten. Without the specific example of Rakuten it would be significantly more difficult for users and guests to assess some of the potentially relevant points in respect of which the question is “seeking advice” on what is common or legal in Japan.
Asking what is common or legal in a specific jurisdiction hardly qualifies as “seeking legal advice”. If the users wish to apply this approach consistently, they will have to remove a significant number of other posts from stackexchange.com as well.
In the other version of the question which is also put on hold the question related to Rakuten’s policies (“Is this just one of the remaining excesses deriving from Rakuten’s Japanese origins that will change somewhere along its way into a truly global company or something that represents the entire corporate culture?”) is a part of the review submitted to Glassdoor rather than a question addressed to users and guests of stackexchange.com. Without including this sentence in the question it would not be possible to comprehensively answer the question addressed to stackexchange.com users and guests. The quote that some users have referred to as the basis for their decision to vote for closing the question ("Questions seeking advice on company-specific regulations, agreements, or policies should be directed to your manager or HR department. Questions that address only a specific company or position are of limited use to future visitors.") would seem to refer to a company you are working for ("your manager or HR department") rather than a company like Glassdoor, which many job seekers are likely to use. I would thus argue that Glassdoor's "company-specific regulations, agreements, or policies" are not "of limited use to future visitors." As workplace.stackexchange.com even has a tag for Glassdoor, Glassdoor clearly is a legitimate topic in the forum.
Lars Friedrich’s answer neglects the fact that Rakuten appears to be merely making the forms publicly available through their website, which is quite different from informing every potential candidate of the request – let alone requirement – to fill them out. It is not obvious from the question that Rakuten is actually informing potential applicants of a “request” to fill out the forms, in which case providing forms at specific web addresses without appropriate links to them in the application and recruitment sites and explanation of their significance in the selection process can hardly be regarded as “making the process public”. It is quite possible that candidates do indeed hear about the “request” or requirement to provide such information from a “shady interviewer” rather than through a public process. Furthermore, the fact that the “requested” information is in fact “necessary in the selection process” may not be public. It is quite possible that asking for itemized salary information and medical history is legal in Japan, while requiring them is not, and this is why Rakuten is not stating the requirement in the forms or elsewhere publicly. Once again, the actual question here refers to what is common or legal in Japan, not Rakuten. However, without the ability to discuss the specific case of Rakuten as an example on the stackexchange.com forum, few users and guests might be able to get a broad enough understanding of some of the issues involved in the question and their potential implications.
It would be more constructive to publish feedback and modification proposals (including this text) on stackexchange.com rather than giving the same users who have already decided to put the question on hold on potentially dubious grounds exclusive access to such comments.