What do underscores signify around words (_words_)?
 

I just need to have my curiosity satisfied. Sometimes on forums or on the net, I see words underscores with words between them. Something like, "This _one_ guitar...", etc. I've Googled multiple times and can't figure out what it means. Is it an underline? That's the most logical explanation for me. But, if it's an underline, just about every forum (at least everyone where I've seen this) has an underline protocol: "This one guitar..." So, I don't get it if that's the case.

Does anyone know or actually use underscores like this?

It signifies underlined. It can also be read as italicized, like when you use underlining for hand-written stuff when you can't do italics. Basically emphasized, but a step down from bold, which uses *asterisks* around the word.

The _underline_ and *bold* conventions are from way back in the day when all you had was a single monospaced font (anyone ever use an ADM 3a terminal?) and no formatting options.

That makes sense, but why don't folks just use the available formatting? ;)

It was driving me nuts for a bit.

Old habits die hard. Some of us have been sitting in front of these screens for 40 years or even more. Plus, tbh, it's often quicker to type a couple underscores or asterisks than stop, mouse, highlight, click format, and then resume typing.

Understood, but I've been staring at screens for about 35 years and started with one line word processors where you would code in underline and bold too. I've always used the formatting tools since I've had them though. I type everything first and then go back and highlight what I want formatted.

It happens when people save a fully formatted document as 'TXT' (not RTF) - the formatting takes the italics, bold or underline info and places it before and after word as underscore lines.

What app does that? I have never seen that behavior before.

Also, on the previous point, there are still places (e.g. text messages) with no formatting capability, so the usage is still there.

I agree and would like to know as well. I have never seen that behavior either.

I'm not sure - it may be in the OCR scanning app some places use - I have seen it in countless eBooks on Gutenberg.org.

I have an editor who can talk about this kind of stuff for hours. She also charges by the hour. I just let her have her way with me, it's cheaper that way. ; )

As mentioned, emphasis. When I do status reports for work I use an underline for such things as headings and bold for greater emphasis.