When responding to RQ or any other request from CIC it is important to carefully read and follow the instructions in the specific form actually received from CIC.
In particular, the RQ form itself has changed multiple times in the last few years, and there are some indications different forms are sent to some applicants.
CIT 520 is NOT a form of RQ. It is exactly what it says it is: a request for specified information or documentation. Again, applicants who receive such requests need to carefully read and follow the instructions in the specific form they actually receive from CIC. The requests vary from applicant to applicant (although many elements are common).
So far as I have seen, all versions of RQ (CIT 0171) ask for information covering, at the least, the full four years preceding the date of application, regardless of when the applicant landed or settled in Canada. Thus, for applicants who apply prior to the fourth year anniversary of landing in Canada, yes, the requested information includes, for example, residential addresses and work history while abroad prior to landing but within the four relevant years.
That is not necessarily the case for supporting documentation. While some versions of RQ have requested more documentation, the last version I have seen did not ask for supporting documentation preceding the date of settling in Canada. Even if it did, not providing this documentation is unlikely to have much if any impact (failure to document address or work history outside Canada does not detract from proof of residency and presence in Canada). Note: this is under the current version of section 5(1) of the Citizenship Act; the scope of relevant information and documentation under the Bill C-24 version will be far more expansive given both the time frame and the "intent to continue residing in Canada" provisions.
In other words, the scope of information requested is typically broader than the scope of supporting documentation requested. So, again, it is necessary to read and follow the instructions in the particular request the applicant receives. At minimum, be prepared to provide address and work history, educational history, and likewise for all immediate family members, for at least the full four years preceding the date of applying. And be prepared to provide documentation which will objectively show or prove that information, at the least for all periods of time claimed to be living and present in Canada, preferrably for at least all time periods since landing if that was within the four year time frame.