One thing that getInstancesIds() might mean is "get the (multiple) ids for each of multiple instances". I don't know why an instance would have more than one i

One thing that getInstancesIds() might mean is "get the (multiple) ids for each of multiple instances". I don't know why an instance would have more than one id, probably more plausible with different nouns, but a similarly named function might return an array of arrays, or a flattened equivalent, possibly uniqued. Probably a bad idea though. I have been guilty (though pleasurably, pridefully guilty) of abusing plurals -- day, days, dayses etc. If you can let the types do the talking that's obviously better, and more descriptive (and less eccentric) names can help a lot with communication and clarity, but there is also sometimes a place for brevity, and for levity.