At the risk of getting all-too-technical for the non-technical, or trying to teach what is unteachable (as in common-sense).
Item 6 in the current application is NOT a trick question. Honest disclosure is the guide.
Nick names should be disclosed in the application. Item 6 in the current application clearly instructs applicants to list nick names.
There is no nick name science or official registry. No nick name police.
Again, honest disclosure is the guide. Such information is not governed by technical definitions.
In the abstract there are no right or wrong answers for items like this. For a specific individual, however, there is the truthful, honest response, versus a deceptive omission. "Little Bill," as his friends tend to call the big guy, is probably OK leaving out "Little Bill" in his list of other names.
There is common sense (and, apparently, all too often, the absence of common sense). "Little Bill," as his friends tend to call the big guy, is probably OK leaving out "Little Bill" in his list of other names.
In the abstract there are no right or wrong answers for items like this. For a specific individual, again, there is the truthful, honest response, versus a deceptive omission. If Gregory Applename has a LinkedIn account under "Greg Applename," he should have disclosed "Greg Applename" in the list of other names he has used. Whether he checks "alias" or "nick name" in the pull down menu should have virtually NO import.
IRCC is not looking for or interested in technically correct responses to items like this. Honest disclosure is the guide.
Thus, no advanced degrees in anthropology or linguistics necessary, no technical engineering necessary, to discern the difference between omitting a pet name, an expression of affection, or a humorous friendly name used by close family and friends, versus a name a person is otherwise known by. Generally, if it shows up in writing or digital communications, better to disclose it in responding to item 6, but the failure to disclose it is PROBABLY not a problem unless that failure is deceptive, unless the failure to disclose it is a failure to reveal a name the person has used in some formal context or is otherwise known by.
Did I mention that honest disclosure is the guide? It is.
So, back to "Little Bill," as his friends tend to call the big guy, he is probably OK leaving out "Little Bill" in his list of other names. If the name on his birth certificate or passport is "William," he probably should list "Bill" in item 6. BUT if only his friends ever call him "Bill" and he goes by "William" in all formal and business and official contexts, probably not a big deal if he did not list "Bill," let alone "Little Bill." However, if he has ever had a drivers license or passport or business license listing his name as "Bill," even if all his more recent documentation all has "William," he better disclose "Bill" as another name used. Common sense.
In the meantime, if Gregory Applename has utilities or a rental or a telephone listed under "Greg Applename," again he should disclose "Greg" as another name he has used. But if in every formal relationship and transaction his name is "Gregory," and he did not disclose "Greg" as another name he has used or is known by, the fact that family and friends refer to him as "Greg" is no big deal. Better to have disclosed it. No problem he failed to disclose it. Common sense lurking around here somewhere.
Consider, for example, "Gregory" does not list "Greg" as another name used. But Gregory gets a request to submit documentation supporting his address history, but his rental agreement refers to him as "Greg." I am guessing that this discrepancy will not be too problematic, but if there are other credibility concerns, other failures to disclose what should have been disclosed, a bureaucratic processing agent is more likely to start connecting dots which spell suspicion. No technical engineering necessary to read this blueprint.
What it is and what it PROBABLY is:
"Probably" pops up a lot above and should also be understood in many of the other propositions stated. This subject, nick names, is not like listing travel dates. When the applicant exited Canada on April 6, 2016, he left Canada on April 6, 2016, and it is wrong to not accurately disclose that date of exit. No "probably" at play.
If an applicant has ever had any formal documents (passport, drivers license, business license, bank accounts) with a name different than what the applicant has entered as his name in the application, no "probably" at play; a failure to disclose that name would be misrepresentation by omission.
But for nick names, as in informally used names, informally known as names, "probably" this or that hangs all over it. Did I mention "common sense?" Did I emphasize "honest disclosure is the guide?"
To correct or not to correct:
Whether the applicant who failed to disclose a nick name in the application should rush to correct this, such as submitting a correction via the webform, is thus a very personal decision. Generally there is no need to rush to make a correction of every minor mistake made in the application. If, however, the omission looms as potentially perceived as a material misrepresentation, better to correct sooner rather than later. As it is often the case: IT DEPENDS. Personally I tend to think it is better to let the system do its thing with MINIMAL interruptions along the way; that is, once the cake is in the oven, not a good idea to try adding some sugar later. That is, once the application is submitted, better to leave it alone if possible. But if information in the application could be perceived to be deceptive, including by omission, then that is something better to correct sooner rather than later. This is a judgment call.
Footnote:
"Baby" may be its own case. You are who you are and it is not a good idea to conceal who you are. So if it fits, wear it. (See definitions by Al Franken, from his comic-writer days, to put this one in context.)
