The intention behind requiring couple's who have been apart for any substantial length of time during their relationship to provide details and evidence is that long periods spent apart
could be detrimental to the stabililty of a relationship - so only if a couple has spent weeks or months apart are they required to provide evidence of how they made efforts to maintain their relationship during those times (so that INZ can see that, even though the couple were geographically separated, their relationship didn't suffer as a consequence).