This looks like a XY problem. If you imply that something would depend on this "identical" word interpretation, it's better to ask a question about this thing itself.

@enkryptor I am not implying anything, I am asking if there is a unique way (under the rules) to interpret the word "identical". I explained two possible ways, the one that I always used and another one suggested in another (=your) answer. I always used the common English sense, but maybe there are others?

I don't think @enkryptor's answer to the other question implies that a dragon and kobolds would ever be considered identical. Seems to me they are just saying that two kobolds are not necessarily identical, as determined by the DM.

@smbailey, enkryptor wrote "The rules allows you, the DM, to decide when the creatures are identical to that extend they have the same initiative" and I asked for clarification in the comments, doing the same example in my question.

What problem are you having where one interpretation or the other would matter?

@StopBeingEvil I just want to know if there is any RAW interpretation of the word "identical" in the rules. Since the two examples (one being the common meaning) that I put in the question seems to generate confusion, I take them away.

@Eddymage I'd advise you do the opposite, to put them back in. They're not what's generating confusion here, if anything they're insufficient. Instead, expand on what mechanical issue you're running into that hinges on how you interpret the word. From what I was able to see, it looked like a question was something like "How does grouping more monsters into a given group initiative roll affect..."

@Eddymage Alternately, if you're finding that there really isn't an underlying mechanical issue that this question is intended to address, if you're purely asking about the definition of the word without such regard for the system it describes, that'd be a question for English Language Learners SE (I think).

@StopBeingEvil I am sorry, but I do not really know how I can put in simpler words as I already done. There is no mechanical issues here, I always used the common English definition (i.e., consider "identical" means "same creature", as in the 1st example). But in the answer linked the user suggested that "identical" may mean whatever the DM wants to mean, hence I wonder if there is a RAW interpretation of this word in this rule for initiative.

@Eddymage You're probably running into this issue then.

After your edit this seems like a duplicate of your last question.

I’m also rolling it back since it invalidated my answer which had already received 15 upvotes.

@ThomasMarkov Actually, I tried to reformulate my question to take into account 1) the observation by Stop Being Evil and 2) your answer, which as you said is already well considered by the community, even if it initially talks about balancing issue, which is not what my concern was about. But I give up, since I can't understand where the problems with this question are.

@Eddymage Personally, I thought the question was fine.

Let us continue this discussion in chat.