On exclusionary language

I remembered once upon time during the days of adolescence where my peers and classmates sought for their identity and for the sense of belonging to a particular group. During those days were the times where everyone had to belong to a group in order to feel “accepted” or “recognised”.
As such, while different groups tried to differentiate themselves from the rest of the community, codes, hand shakes and sometimes to the extreme, even crests were born. In all desperate attempts to paradoxically “individualise” “groups”, the F language was born.
The F language, although ironically should only be understood by a certain group, presumably the group who first came up with it, begin to proliferate amongst the rest within the community for example, our school. Slowly, it began to even manifest itself amongst teenagers or people of my age and before anyone realises, almost everyone on the street who were of the same generation could speak the F language. An attempt to differentiate one’s group failed miserable as in-groups did not keep to their part of the bargain—to maintain the group’s “code” language.
What’s all the ranting about? I am not trying to forcefully share a part of my adolescence-hood with you good readers but rather, I am trying to raise a point that even though a group can make use of exclusionary language, the extent of “exclusionary” can only go as far as the tightness of the lips of in-groups. This whole argument about exclusionary language is only but a theory or a concept which is very flexible.
Exclusionary language, as its name suggests, refers to any forms of terminology or jargons which are supposedly shared and only understood by a certain group within its in-group members. The fact that the in-group members are the only ones who understand the language separates or excludes the rest from the former. However, how exclusive is this exclusionary language? Alas, but it can only be exclusive unless in-group members decides to be “nice” and educate friends and fellow peers who are technically considered out-group in an attempt to look “cool” or to boast about their group. This brings me back to my point that exclusionary language is a very flimsy, or rather, flexible concept although it does a good job defining terms and jargons which we may not understand, never mind that we may one day be so lucky as to be educated by one of them in-groups regarding these “foreign languages” or shall I say, “exclusionary language”?
Delving deeper into thoughts about exclusionary language, I have to further elaborate that sometimes, exclusionary language can include jargons or terms used by professionals. In these cases then, the “exclusion” that it has on people should be thought of as a subtle and unconscious form of exclusion. This would probably be easier understood in a story form. Imagine you are a doctor and you have spent more than six years studying terms which are far from lay man’s and it is all internalised within you thanks to the millions of tests you have gone through. One day while you were having coffee with your friend (who is anyone else but a doctor) when suddenly you have a headache at the back of your head. Instead of saying “oh no, I have a throbbing pain at the back of my head” you say, “oh no, I have a muscle tension stretching across my occipital lobe from the medulla.” How is your friend going to react to this? You did not use these jargons on purpose but because it was internalised within you, it came out automatically as compared to the previous example whereby groups come up with codes or languages specially to exclude people.
This concludes the point that exclusionary language can be both subtle and blatant as with the two scenarios I have described above.