I've studied linguistics - to a limited extent - and I've found that there is an interesting similarity between personality typing and linguistics. Speech patterns can be broken down from broad categories to more isolated categories. The most broad category of speech is a language. However, there are close deviations from specific languagues - these are dialects. Further, different languages can have a relationship - e.g., by descending from a common language. Also, within dialects, there are idiolects - the peculiarities of a specific individual's speech.
From studying socionics, I've noticed that personality typing follows a similar pattern. Just as different languages can be related, different personality typing systems can be related (e.g., the MBTI and socionics). Further, within each personality typing system, there are different movements (e.g., Filatova's interpretation, socionix, etc.); these are like dialects. Finally, every individual socionist has their own interpretation; these are like idiolects.
What does this mean? Well, just as there might be a different word for "soap" in different languages, dialects, or idiolects, a particular function or typing can be different to different individual socionists. This makes me wonder: if different socionists type people differently, does one have an "official" type? Well, unlike languages, socionics is not arbitrary; while the word "soap" could be used as a symbol for anything, Ne characteristics would not normally be confused with Se characteristics. However, there is still a certain degree of ambiguity in socionics. For example, what one socionist will classify as Ne behaviour, another might classify as Ni behaviour. The question is which classification is more accurate, but the problem is that socionics concepts are vague enough that there is a certain margin of error; we cannot understand human behaviour well enough to separate Ni behaviour from Ne behaviour all the time, with 100% accuracy. In other words, you can't always come to a clear answer about someone's type - even your own. How often does this happen? This depends on the degree of difference amongst the descriptions. And from reading many descriptions, I've noticed that socionics can be quite inconsistent, so I would expect it to happen fairly often.
Keep this in mind if you're having difficulties determining your type, as it's sometimes better to draw no conclusion than an arbitrary one (or maybe a more general conclusion, such as being an Alpha, as opposed to being an LII).
The solution to this problem would be for socionics to provide more consistency, and this would be achieved through empirically derived standards similar to what the MBTI has done, but without turning socionics into a testing business.