The bot tells me |26.i12 would have won. For example 27.g13 28.f13 29.e14 30.e11

The bot tells me 26.i12 would have won.

David, you are constantly making an issue of the use of the vertical bar. I have tried to understand the difference, but can not get a handle on it. For example, I copied your text as written, but deleted the vertical bar. I can click on either message, and I see no difference.

Perhaps you can create an illustrative example in this thread?
(meow)

The vertical bar forces Twixt Commentator to treat it as a branch off the mainline.

If there is no vertical bar, it looks for step N-1 in previous text within the scope of the comment, and if it finds it, it branches from that, so that you can have intervening explanations within a branch you're exploring.

MCx = MisterCat extra, in case you wondered.

OK Alan, thanks for the words. Since you wrote the software, you naturally understand it. Your post has not cleared it up for me at all. It seems that my experiment above, where the vertical bar made absolutely no difference, was limited because I was only looking at one simple line in the post. I think that you mean that, within a post with multiple and alternate lines of analysis, the bar brings each line to the same starting point? And if no bar?

Well, that means I must try a more detailed experiment, so here goes:
(there should be no expectation for the quality of lines I make up)

The bot tells me |26. i12 would have won. For example 27. g13 28. f13 29. e14 30. e11
However, after |26. h11 27. f12 28. e12 29. g10 30. g13 black is lost.
But in case of |26. i12 white can try 27. g13 28. f13 29. e14 30. g11 31. d12 32. e10 33. d10 31. c11 32. b11 and white wins this time!

Now to repeat those comments with extra bars starting each follow up line:

The bot tells me |26. i12 would have won. For example |27.g13 28. f13 29. e14 30. e11
However, after |26. h11 |27. f12 28. e12 29. g10 30. g13 black is lost.
But in case of |26. i12 white can try |27. g13 28. f13 29. e14 30. g11 31. d12 32. e10 33. d10 34. c11 35. b11 and white wins this time!

Now with all vertical bars removed:

The bot tells me 26. i12 would have won. For example 27.g13 28. f13 29. e14 30. e11
However, after 26. h11 27. f12 28. e12 29. g10 30. g13 black is lost.
But in case of 26. i12 white can try 27. g13 28. f13 29. e14 30. g11 31. d12 32. e10 33. d10 34. c11 35. b11 and white wins this time!

And a weird one - one vertical bar at the very start, and only one more vertical bar placed in the middle of the last comment.

The bot tells me |26. i12 would have won. For example 27.g13 28. f13 29. e14 30. e11
However, after 26. h11 27. f12 28. e12 29. g10 30. g13 black is lost.
But in case of 26. i12 white can try |27. g13 28. f13 29. e14 30. g11 31. d12 32. e10 33. d10 34. c11 35. b11 and white wins this time!

This is getting tiring. Hopefully these various setups will show some differences that illuminate the situation. I won't know until I post this comment and try it out! (meow)

A few formatting errors in above post, but here's one thing I perceive. Suppose I wish to examine a NEW move 26 and follow that up with analysis starting at move 27. A vertical bar at move 27 IGNORES my commented move 26 and REPLACES IT with the ACTUAL move 26 from the game. OK then - a vertical bar at any point will IGNORE any text comments that precede it, and the comment starting with a vertical bar will start from the position in the actual game.

OK so far?

But what I am failing to see is a PROBLEM with leaving out all vertical bars entirely. It would appear that my 3rd example, with no vertical bars, simply and correctly shows different comments and different lines in the game, all using the starting position from the actual game. This seems perfectly fine to me.

So are we talking about a case where a comment is made - say moves 26 - 34 are DIFFERENT than what was played in the game, but the same poster wants to branch off - say, keep his commented moves 26 - 30, but then at move 31 we branch. Oh, but here I am still unclear, since a vertical bar at move 31 would IGNORE our commented line moves 26 - 30, so one STILL would want to leave OFF the bar?!

OK, my head is spinning. If you'd care to enlighten me further, Alan, it would be appreciated (and perhaps of use to other readers - don't know for sure; maybe I'm the only numbskull here). Maybe you can make up a few concrete examples, as I did here, to illustrate.
mc

and David, I am not leaving you out. Your comment to Steven:

The vertical bar means this is the first move of a variation from the game. If you add the bar to the middle of a variation, when you click on the moves you get the wrong position. Usually just one vertical bar at the first move of your comment is all you need, unless of course you want to discuss more than one variation from the game. If you click the Preview button and then click on the last move of each variation you produce, you can verify that you are creating the variations correctly before you click the Comment button.

is already making more sense to me NOW that I've done all this work, but this is what started me out on all this.
mc

I forgot to mention, there is an additional hazard to not using the vertical bar. Try this: click on move 23 in the game (main variation). Then add 2 more random nonsense pegs directly by clicking on the board, that do not match anything in the game or any comment. Observe that your current variation has moves 24 and 25 in red. Then click on your move 26 without the vertical bar in your comment. It continues from your variation! You are exploring a variation that does not exist in your comment. Now, don't ask me to fully explain my design decisions from over 10 years ago, but that was by design. I added the vertical bar feature because I saw that long comments were easily getting muddled by these rules meant to make it easy to explain and explore variations.

I tried it both ways. So, if one explores a few different moves for 24 & 25 but then wishes to continue looking at the game from move 26 in the original list -

If you wish to continue analyzing from move 26 WITHOUT paying attention to your proposed moves 24 & 25, then the vertical bar WIPES THESE OUT. Of course, you could have wiped them out by hand, either by deleting them or by going into the original game text and clicking on move 26.

On the other hand, if you want to include your proposed moves 24 & 25 and continue your analysis of a proposed line from move 26, then OMIT the vertical bar. Your moves 24 & 25 will still be there, and you may now step forward from move 26. This doesn't seem so bad to me. I guess there might be a possibility that Commentator will get confused by the new moves 24 & 25 as you step forward and a conflicted position may arise. Actually, I'm not sure if this is a real risk.

It DID HAPPEN back when David and Steven were analyzing a game 2442066 . Steven OVERUSED the vertical bar, and created a comment that Commentator could not step through. That was Steven's 2nd comment in that thread. He should have NOT put a vertical bar there.

All this seems to show that the use of the vertical bar is PRACTICALLY UNNECESSARY. Personally, I am not a fan; have to hunt for the key every time, and it slows me down. I believe that I have NEVER used it in any of my various comments in all these years, and there was never a problem caused by that.

I'll leave as an open question then - are their cases where using the vertical bar is absolutely necessary, as you will get messed up without it? I can't seem to create such an example. (meow)

If your comments are short, or only discuss 1 variation, there should not be much difference.

MCx, you want an example where not using a vertical bar would result in generating the wrong position. A simple example is if I first talk about an early variation from the main game, for example |9.n9 10.n6 11.j7 12.m12 and then I change the subject and want to talk about a variation which deviates from the main game at move 13. If I just enter the moves as 13.q5 14.r5 then when you click on these moves they will be interpreted as a continuation of the previous variation beginning at move 9. You would need a vertical bar |13.q5 14.r5 to get to the intended variation.

You could avoid a vertical bar in this case if you mention the later variations first and talk about earlier variations later in the same post. This is also a good policy when talking about sub-variations of the same variation, to avoid listing the same moves twice.

The vertical bar is probably not strictly necessary if you are careful, but if you don't use it then if you click on the moves in one post and then click on moves in another post, or like Alan says if you make your own moves on the board and then click on a post, you could wind up with the wrong position. I find the bar useful just as a bit of extra security and way of organizing my thoughts.

Does this make sense to you?

Also you don't have to hunt for the vertical bar key. Make the moves on the board, then copy the moves, being careful with your mouse to include the vertical bar at the start of every generated move list.

Peyrol, thank you for your additional examples. This is illuminating, as was Alan's explanation. I really don't post here all that often; used to post a bit more, but not lately. I think my posts were all extremely simple lines, not multiple lines, so I never used the bar and apparently didn't need to. I'll try to remember these examples, so in the future I'll know when I should use it.
Oh, how does the mouse help you with a vertical bar? You still need to hunt for it on your keyboard - mine is on the right, underneath the backspace, and requires shift. Not all that difficult, but still a task for a lazy typist. McX

Make some moves on the board. Look at the generated move list highlighted in red. At the beginning of this move list is a vertical bar. You don't have to type the vertical bar key. Just copy the vertical bar with your mouse, along with the generated move list, to paste into a comment. I am repeating what I just said in my previous post. I wasn't able to communicate then, so maybe I'm not getting through now either.