"can [do something] only in [some manner]"

If you can do something only in some manner, that does not imply you can't do it in some other manner. It states it.

I hope that answers your question. The presentation [. . .] is awkward to work with.

I meant "imply" in the logical sense rather than the everyday sense.

Let me rephrase. If I say I can mop only tile floors, do you know that I can mop tile floors, or do you only know that I can't mop carpeted floors?

Yes. It is obvious to me that you can mop tile floors.
This seems so obvious, I am having a hard time understanding why you need to ask, however i am aware such things are not always clear to ESL.

Your sentence structure could use improvement.
I can only mop tile floors

Actually, English is my first language (and the only one in which I'm fluent). If this forum is meant only for ESL, I apologize; I was unaware. I'm having trouble finding an English grammar forum that isn't dedicated to ESL.

I also would prefer to write "only" immediately after "can" in a sentence such as this, but I'm asking because I'm having a dispute with someone in a different forum. We're trying to interpret a particular piece of writing that is written with the template I used above.

I was under the impression that it's only an assumption that I can mop tile floors given the clause in my example. From outside reasoning, one can conclude that I probably can mop tile floors (i.e., why would I use that particular phrase if I couldn't mop tile floors?), but is that meaning actually encoded in the phrase?

For an example of what I mean, suppose a sign says, "you may buy alcohol only before 10 PM." If I'm under the legal drinking age, I still can't buy alcohol before 10 PM.

"you may buy alcohol only before 10 PM." means that the ability to purchase alcohol is exclusive to the hours before 10 p.m.

Your addendum: "under the legal drinking age, I still can't buy alcohol before 10 PM." is a tangent and has nothing to do with your original question.
*************************************************************************
If you can walk only when chewing gum, then you can walk and chew gum at the same time. But don't try walking without the gum. That doesn't say you can't just chew gum without walking, however.

By the way, I meant for that to be, "You can buy alcohol only before 10 PM."

Anyway, I don't see how the exact point of my original question can have nothing to do with my original question. In this context, my original question is, "Based on the sign, can I conclude that I can buy alcohol before 10 PM no matter what?" I believe the answer in that particular case is, "No; if I'm underage, I can't buy alcohol before 10 PM."

In my understanding, the sign assumes that the place of business in which it's posted sells alcohol, and it assumes that the reader knows that, meaning that the sentence on the sign provides only a restriction on a permission that's already assumed. Is that understanding more or less reasonable than the position that the sign emphatically states that you always can buy alcohol before 10 PM, and it's simply wrong?

You = qualified buyer.

The sign means nothing to anyone else.

Your knowledge of how the English language works could use improvement, Dadpad.

So, would you agree that the sign restricts an existing permission without granting a permission itself? That is, essentially, my claim: if one can do something only in a particular manner, the question of whether they can do that thing in that manner can't be answered using only the given information; knowledge or an assumption of ability or permission must be supplied from elsewhere.

Great! You seem to have answered your own question to your own satisfaction.

I believed from the beginning that I knew the answer, yes. I implied as much earlier. However, as I mentioned, I'm trying to convince someone on another forum that my answer is correct. Actually, I was expecting an immediate agreement from everyone here because I thought this was common knowledge. Apparently, it's not; I met the same answer on a different forum. Anyway, can I take it from your reply that you see no errors in my reasoning, or is the meaning of your post limited to the implication that you find me tiresome?

Watch whre you put that word, "only"

You can only buy . . .

You can buy only . . .

It makes a difference.

Howdy, Punkey.

==================

You can only buy two.

You can buy only two.

No difference there.

=================

You can only buy mine.

You can buy only mine.

No difference there either, Punkey.