Foremost, proper translations are required for ANY document that is not in English or French. This is explicitly stated in the Instruction Guide for citizenship applications. There are a dozen or more references to providing translations in the Instruction Guide.
Moreover, this is standard IRCC policy. Any information in any document submitted to IRCC containing information not in English or French, for virtually any application to IRCC, must be accompanied by a proper translation. PRs have been down this road before and should be well aware of the drill.
While the checklist item for including a translation only applies if there is non-English, non-French information in the documents submitted with the application itself, it is consistent with the general policy and specific instructions, that for any document being presented to IRCC anything in a language other than English or French needs to be accompanied by a proper translation.
So a passport containing stamps, visas, notes, whatever, not in English or French, does not need to be translated for making the application itself unless the information is on the biological pages of the passport. But by the time the applicant appears for the interview, at which the applicant is required to present the full passport, anything in the passport not in English or French needs to be translated. That's the rule. That's the instruction. Posts to the contrary above are simply outright wrong.
That said:
As in many aspects of the process, BEWARE accounts of personal experience without recognizing context, variables, and vagaries. What worked for one person does not necessarily indicate what will work for another. And the contrary, just because one person had to do this or that does not mean someone will also have to do that.
When it comes to the requirement that any document submitted to IRCC containing information that is not in one of the official languages be accompanied by a proper translation, it is not surprising this has not been uniformly let alone universally enforced. For one thing, IRCC is not engaged in a gotcha approach, so context matters. IRCC lets slide all sorts of minor failures to fully follow the instructions (benefitted from this myself), but that is a long, long way from suggesting that IRCC will generally not enforce the instructions.
Overall, many report (like I can from my own experience) that they had information in their documents (stamps in passports being the most common) which was not in English or French, did not provide a properly authenticated translation, and did not encounter any problems because of this in the interview, no request to provide a translation. In my case, I took the oath less than 48 hours after my interview.
But many, many more also report that, at the least, they were required to submit proper translations after the interview, and some report the failure to provide proper translations appeared to cause issues at the interview and being subject to lengthy delays in processing.
I had simply overlooked that I had a small amount of information in a couple stamps that was not in English or French, but those stamps were otherwise easily read and were dated outside the relevant time period for assessing my residency. I do not know if the interviewer even noticed that the stamps contained a small amount of information not in English or French.
I would anticipate that in addition to how much information there is in a non-official language, how readily the information can be understood without translation, what probably factors into whether the requirement is strictly enforced can depend on whether the interviewer has concerns about verifying dates or travel, or other concerns. In other words, who IRCC will let slide versus who will be subject to strict enforcement of the requirement to provide translations, undoubtedly varies widely from person to person and in part depending on how solid and convicing the application is on its face.
I am tempted to say that personally I would not risk going to the interview without a translation . . . except I did, inadvertently. Perhaps I have spent way too many years in North America, so I do not always practice what I preach.
But make no mistake: translations are required. That is standard for almost all IRCC applications. It is explicitly instructed for citizenship applicants.
