- My guess is that the Blogger help people are right. Sort of.
Word, and probably all word processing software, puts tags or other code in your text as you type. That's how it 'remembers' which text you specified as italic, bold, whatever.
It's very handy, but can cause issues when moving text from one word processing program to another: or, in this case, to Blogger.
Blogger uses html tags, which appear when using using the HTML tab - the tags are hidden when using the Compose tab, letting you see the text with (some) of the formatting that will be in the posted version.
Happily for me, I learned the basic html tags several years back, and routinely compose in Blogger, using the HTML tab. I go to the Compose tab when editing text that's got many tags in it.
As far as I know, editing in a text editor, like Microsoft's Notepad, which has no
text formatting options aside from 'wrap' or 'don't wrap' and the font it displays, would present no issues.
I've very often saved a post to Notepad, repasted it later, and experienced no issues.
I hope this helps.