You mean a number sign?
This is the one of mine.
The other, more annoying to some people here, is not to worry so much about any grammar or punctuation when I’m on the web like this. Writing (as in actual letters) I am fanatical about it but to me anything electronic is more a form of speech or short-hand. Formal rules go out the window.
sheep, moose, etc. Words with the singular and plural being exactly the same. I’m willing to say ‘a herd of sheep, moose, etc.’, but I’ll be danged if I’m going to say ‘there are two sheep, moose, etc. by the road.’ So laugh if you must, I will continue to say ‘there are two sheeps in the field’ and ‘there are two mooses in the woods.’
The rule is a little more complicated than that. If you are quoting someone yelling “Bloody 'ell!” that’s how you write it, even if it’s the end of the sentence. However, if the emphasis is yours, as in
then the punctuation goes on the outside.
That goes only for everything except periods and commas; those always go on the inside (in America: you Brits can go do something else). Colons and semi-colons go on the outside, except in the rare case that you truncate a quote on the punctuation mark, so it is actually part of the quote. Same with dashes, parentheses, and soforth. Punctuation goes inside parentheses when it contains a complete sentence, and on the outside when it contains a fragment.
Although my wife ridicules me, I stoutly maintain that the state name is pronounced “Warshington.”
I am the same.
I had a boss with whom I shared a deep personal dislike. One day, she called me in to correct an order for a 30 pound weight. I had written “30# weight” on the line item. She shook her head condescendingly at me and handed back my file. “BeeGee, JUST because it’s called a pound sign on the PHONE, it doesn’t MEAN pound like the weight.”
I said “I’ll change it because you’re the boss and I’m not. But it does mean pound as in weight.”
I did get to sit quietly at my desk and overhear next higher up boss tell her she was wrong.
“Ain’t” shouldn’t have an apostrophe in it. What the hell is it a contraction of?
Here you are, sir.
Sounds to me like it should have several apostrophies - ain’‘’‘’''t. 
About slashing zeroes and letter "O"s, In the 60’s I did both Fortran (typically slashed zeroes) and COBOL (typically slashed "O"s)
[QUOTE My wife is both a possessor of, and an expert in, the female reproductive system. I’ve never heard her get as pedantic about the names of the bits as some folks on the Dope. When her patients tell her about their vaginas, I’m pretty sure she can figure out from context what they are saying. Around her colleagues, I’m sure she’s more precise. But somehow I doubt she’s ever said to a patient, “Pfft. I think what you meant to say is that you have a painful sore on your vulva.”[/QUOTE]
Of course, your wife knows the popular usage and has to deal with her patients accordingly. What is interesting is that apparently many women learn a colloquial language which names her entire structure down there as the vagina and which, not coincidentally perhaps, is the most important part of a woman in influential segments of a male-dominated culture . Of course, this point of view becomes imbedded in the entire culture, essentially telling the women that all that labia and clitoris stuff is not all that important, and that its that VAGINA down there which gives you value.
Do you put an apostrophe in “won’t”?
The empty set sign is similar to, but not the same as, the slashed-zero. On a slashed zero, the slash terminates at the oval. On the empty-set sign, it extends beyond it.
I do the same, except I usually abbreviate the month to three letters. It’s not for ease of sorting, and it’s not because it’s the convention in use by any particular other people: It’s because it’s impossible to misinterpret. 04/12 could mean the 12th of April, or it could mean the 4th of December, or it could mean April 2012, but “17Apr2015” can’t possibly mean anything but today’s date: The four-digit number must be the year, and the abbreviation must be the month, and the two-digit number must therefore be the day of the month. Putting them in that order separates the two numbers, so even smooshed together like I did, there’s no confusion over which digit is part of which number. Though I suppose that “2015Apr17” would work just as well.
I also have a problem with “won’t”.
Well, really, it doesn’t matter what the first part of the contraction stands for; the apostrophe is just to stand in for the “o” in not, which is still there regardless of what the first part of the word is trying to be.
Or just write “aint” and “wont”. Won’t bother me none; ain’t no thing.
You sure you aren’t thinking of the “thirty aught six” (.30-06)? That is how that chambering is typically referred to but I have not heard the “three oh eight” said that way. Could be a regional thing.
Maybe one of your ancestors was doing it in the 60s… the 1160s.
I find the Model 33 reference particularly comforting. I spent waaay too much of my misspent youth camped in front of an ASR 33.
That my way is the correct way to do just about anything! (It is the best way.)
My poor wife.
Actually, it’s a 7.62 
I used to have a co-worker who pronounced her car name as “Vulva.” I think she did it on purpose, she was that kind of gal.
My ineluctable but untrue fact is the origin for calling gingko trees “maidenhair.” I contend that it is the fan shape of the leaf that mirrors the untouched shape of a girl’s pubic hair. Apparently I am wrong. But I still think it works.